The Filming Timeline
Judging from all the available evidence so far, this is how I believe events unfolded. I'll update this with new info as I get it. Note: Some of the items here may be in error, but they represent my best educated guess about the sequence of events as they happened.
Here's the timeline:
1. May 23rd, 1986-"Poltergeist II: The Other Side" is released nationwide and has a great opening weekend. Early the next Monday, MGM execs call writer/producers Michael Grais and Mark Victor at their office on the MGM lot and ask if they'd be interested in working on "Poltergeist III." The thought of going into "Poltergeist Land" so soon after spending an exhasuting two years from writing to delivery of the second film prompts "both their mouths to hit their desks." They both feel it is time to move on. They may not have refused to do the film that week, however. They may have waited to see the final box office talley of "Poltergeist II" before finally ruling out the next installment. They also may have held out to see how much MGM was willing to offer them for another sequel. While P2 was profitable, it was not as succesful as the original film. One possibility is that Grais and Victor may have had a stipulation in their contract that they had first refusal on P3 if P2 didn't make above a certain amount. When P2 ends up making about 41 million dollars compared to the original's 76 million, they pass on P3.
2. June-September 1986: During the next four months, MGM considers asking Craig T. Nelson and Jobeth Williams whether they'd be interested in doing the next installment. Because Craig and Jobeth are not under contract, they hold out for more money than MGM is willing to pay. MGM realizes this and decides that they can still make another film as long as they have Heather O'Rourke. MGM execs Jay Kanter and Alan Ladd Jr. contact director Gary Sherman to ask if he'd be interested in writing, directing, and executive producing P3. Gary apparently had been on the short list as one of Grais and Victor's director choices for P2, so that would explain why Kanter and Ladd went to him first. Gary had also worked for Kanter and Ladd at another studio. Gary is told he can pretty much take the story in any direction he wants to. What the execs mandate is that Carol Anne be put into a completely new setting. Gary comes up with the idea of having Carol Anne stay with relatives in Chicago. He also opts to keep the Rev. Kane in the story, even though Julian Beck passed away. MGM plans to make P3 for a lower budget than the last film. The SFX budget on P2 had ended up costing about twice as much as originally planned, with many of the concepts being changed or scrapped altogether. Sherman tells the execs he plans to control costs by shooting most of the effects sequences live on the stage rather than in post production. Money is also going to be saved because of the absence of stars Craig T. Nelson, Jobeth Williams, Oliver Robins, writer/producers Victor and Grais, and composer Jerry Goldsmith.
3. October-December 1986-Gary and his writing partner Brian Taggert begin developing and writing the script for what is titled "We're Back: Poltergeist Continues." Gary feels it is important to get at least one other member of the "Poltergeist" cast back on board-actress Zelda Rubinstein. Zelda is invited to the November screening of the opening of Gary's new movie "Wanted: Dead or Alive." After the screening, Gary introduces himself to her and says they will soon be working together in "Poltergeist III." She hadn't even known there was going to be another sequel at that point, and is charmed by both Gary and his new film. In addition, it seems that Zelda may not have read the fine print of her contract for the original film, which apparently obligated her to do at least two more sequels (likely for a set rate). So, she didn't have the bargaining power that Jobeth and Craig had (this information was claimed by a guy on the IMDB who said he spoke to Zelda once at a party in Florida. He said she expressed frustration with MGM for the way they treated her on the sequels). Also that month, MGM Chairman Ladd tells visiting journalists that Sherman and Taggart are developing P3 and that it will be filmed in 1987.
4. January-March 1987-the film is in pre-production. It will be shot on location for about three months in Chicago, with much of it done on soundstages there. The film will be shot for about half the cost of the last sequel, 9.5 million to P2's 20 million. Producer Barry Bernardi hires legendary makeup man Dick Smith as a consultant on the film. Smith in turn recommends Doug Drexler and John Caglione to actually create the makeups. They are hired and plan to work mainly out of their new studio in Brooklyn, with visits to Chicago during filming. In February, Heather fails the cast physical but is cleared for work before leaving for Chicago in April. In March, screenwriter Steve Feke is brought to Chicago during the leadup to the start of principal photography to do a "polish" of the script. He is uncredited on the final film (he may have also stayed around during shooting to touch up some other scenes).
5. Principal photography is completed on location in Chicago between April 13th-June 19th, 1987 (shooting may have gone as far as the end of that month). All of Heather's scenes are finished. At the end of June, a wrap party is held for the cast to celebrate the completion of shooting. This cast party was hosted by a Chicago company called "Dance all Night" and is confirmed here:
http://www.danceallnight.com/pictures.html
6. July-September 1987-Post production begins at the MGM studios in LA-sound mixing, editing, scoring, etc. As reported by "People" magazine, to celebrate the end of shooting, Heather and her family spend July and August driving from Chicago to Disney World in Florida and then back to CA. In September, Heather begins the 7th grade in San Diego.
7. October, 1987-Post production work is nearing completion. At the ADR looping sessions, Corey Burton, who provided the voice for Kane, is informed by Gary that they won't waste studio time looping much for the ending, since it will "likely be re-worked anyway." Possibly in early November, Gary Sherman flies to NYC with a VHS rough cut of the film. SFX artists Doug Drexler, John Caglione, and Gary drive up to Dick Smith's house in Larchmont, NY to screen it. While Gary is enthusiastic about the film, the others don't think it turned out all that great. While in NYC, Gary apparently also screens the rough cut of P3 at the World Trade Center for a group of film industry professionals and distributors. This is the screening that Macklin Crux saw. The assembled group likely viewed the same tape Gary screened in Larchmont. Macklin says:
"Yes, several people were from the studio and several people were from the
SFX group in Brooklyn. I want to say color array projector (would suggest
VHS Tape) but I vaguely recall a very loud film projector .... not sure."
He remembers the ending of Kane touching the necklace (and thinking "how cheesy") and the frozen bodies, as well as the scene of Carol Anne, crying, waving goodbye to Tangina in slow motion. He recalls that for some of the effects scenes (possibly a couple of the rare shots involving optical effects), they saw sketches to indicate what the final effect would look like. He also said there were no credits on the film and very little music.
Apparently even in this early cut, although Gary had intended P3 to be the end of the trilogy, MGM decided they wanted an opening for another sequel. According to Mr. Crux, he seems to recall that the lightning strike which appeared in the final film version was also in this early cut:
"There was a clash of thunder over the skyscraper in the ending I saw and it was suggested that 'it wasn't over' (Kane's wicked laugh)."
There appears to be supporting evidence for this in the "making of" featurette for the film. "Poltergeist III: The Special Effects" has a copyright date of 1987, and included a quick, rough sketch-type shot of two lightning bolts striking the highrise. Shortly after the WTC screening, post production work is completed.
8. The week of November 16, 1987-the completed film is submitted to the MPAA ratings board. The next week, in Bulletin #986, November 23rd, the film is given a "PG" rating. This may have displeased the studio execs, who were likely looking to get the demographics (young, teen males) of a PG-13 rating. In addition, Gary Sherman may have been under contract to deliver a PG-13 film.
9. December 1987-Gary and his team go back to Doug Drexler's and John Caglione's lab in Brooklyn to discuss changes to the ending. At the entrance to the lab, Doug places a photograph of one of the "evil Carol Anne" makeup shots with a post it note that Gary will see when he walks in. The post it says "This makeup did not get ONE closeup!" Gary tells them that since "Tangina accomplishes Kane's death," he'd like to see Kane transformed on camera into a corpse. In the original ending, Kane touched Tangina's necklace, and his face then "exploded with light." Here's how Doug describes that effect:

10. Gary requests that the new version of Kane's decomposistion be done without the use of stop motion, optical effects, or undercranking the camera. Doug notes that he thinks "Zelda should not come back at the end. It's very confusing."
11. Doug Drexler, John Caglione, and Dick Smith get to work on creating the new version of Kane's decomposition. Doug makes notes and sketches from December 1987 into January 1988 on how the effect will be done. It is planned that after Kane touches the necklace, a waist up dummy of him will be used. It will rock back and forth, an internal mechanism used to move its eyes and mouth. Air will blow upwards, shooting his hat off the top of his head. Meanwhile, intense heat from nearby propane blowers will melt the rubber face of Kane, thereby creating the decomposing effect without the use of stop motion or other post production tricks. Dick creates 6 of the wax Kane masks. One of them is placed over the "articulated Kane puppet head" and some tests are run using the propane blowers to melt it. These SFX shots are photographed. One of the masks ended up being used on set in the re-shoot, and the remaining four were later stored in John Caglione's garage, where they remained for years.
12. The film's production manager, Ed Ledding, tells Doug that the budget for this new sequence has not yet been approved, and the actors are not availiable for the initial shoot date. As a result, the effect should be in "hold" mode.
13. February 1, 1988, Heather passes away. The initial plans for the scheduled re-shoot are put on hold. The funeral for Heather is held that same week. MGM issues press releases saying that Heather had completed the film and it will be released as scheduled in June of 1988.
14. Behind the scenes, however, no one wants to finish the movie. In fact, some urge the studio to shelve it, at least temporarily. The MGM board, however, allegedly tells Gary and Barry Bernardi to finish the film or they will get someone else to do it. It's perhaps even more important now to re-shoot the climax because of the fact that Carol Anne's "frozen body" is seen in the original ending (I also seem to recall years ago someone else telling me that Jim Peele, Heather's step-father, said a scene of Carol Anne encased in ice was cut from the film). Macklin Crux has his own theory on how MGM may have dealt with the film at this point:
"After her death, it was clear they could not ride the Heather train to success for two reasons...It didn't work and she had passed away but would if they played up"The Final Chapter" [aspect] and changed a few things to bring an end to the saga. This would have been a clever marketing strategy to sell the film to the public."
15. In early March, Doug and John are told that the re-shoot will soon commence. They have a very short time to finish the "articulated Kane puppet head" they've been working on. They manage to get it ready in 12 days. They also create two "decomposed" bodies for Bruce and Donna to replace the "frozen" bodies of the family. Gary re-writes, again, the script they had been planning to use for the ending of the movie.
16. On March 7, 1988, a WGA (Writer's Guild of America) strike begins. Most TV and some film production shuts down.
17. The new pages are marked "Revised, MARCH 14, 1988" (apparently the first day of filming). There is a possibility that there was a violation of WGA rules since these pages were "Revised" after the beginning of the March 7th strike. Perhaps this is why MGM never mentioned the re-shoot at the time, and why to this day Gary Sherman refuses to admit that a re-shoot even took place nor when the "bullshit ending" (as he terms it) was filmed (he seems to have indicated to the E! True Hollywood Story people that he "finished" the film "in one day" in the month of February, shortly after Heather's funeral. However, this is clearly not true, since 1.)there WAS a re-shoot which took at least a week and 2.) it took place in March).
18. In the emotional and logistical turmoil after Heather's death, not many people are still around for the film. Apparently, the studio execs decide to leave Kipley Wentz's character "Scott" out of the new ending, perhaps because they think it will confuse the audience to see him again, thus making the Scott who comes out of the pool (originally intended to be the "evil Scott") the "real" one instead. The sequence where Tangina shows up to lead Kane into the Light is added, along with the scene of Bruce walking out of the mirror with Carol Anne and Donna. It may have been thought that the scene of Carol Anne waving goodbye and crying in the old ending would not be appropriate after Heather's death.
19. Monday March 14th: the re-shoot begins. The scene where the mist clears and Pat says "She did it...she saved us!" is probably filmed first, since it didn't really require any heavy duty effects, along with the fact that Lara Flynn Boyle was only available for one day. The scene of Bruce walking out of the mirror with the double of Carol Anne is likely filmed later in the week. A double for Lara Flynn Boyle was used in that scene, since Lara had to get back to her other movie. She was in LA filming the movie "How I Got Into College." In fact, its first day of production was Feb. 1st, the same day Heather died. There is a mistake made in the costume department-the double for Carol Anne is wearing white sneakers over her red PJs for the scene where they're walking out of the mirror.
20. The more elaborate makeup effects are filmed later. The final scene of Kane decomposing is filmed Friday, March 18th. By this time, instead of having Kane touch the necklace, Pat uses the shovel to slice his head off, and the head rots on the floor. After this effect is filmed, Gary says "It's a wrap." Doug and John go back to NYC.
21. On Monday, March 21, 1988, an article appears in the "LA Times" titled "MGM Ponders Selling of 'Poltergeist III'"
Producer Barry Bernardi is quoted as saying he doesn't belive any scenes need to be edited in light of Heather's death. It is mentioned that the studio plans extensive audience reaction screenings. The article makes no mention of the re-shoot which took place the previous week; as mentioned above, MGM may have been trying to keep it quiet because of the WGA strike (though the horror SFX magazine "Gorezone" would print an article written by Doug Drexler called "Poltergeist III and a half: The Reshoot," in September of that year).
22. Apparently after these screenings, it is decided to keep the lightning bolt at the very end. Sherman didn't like this, especially after Heather's death. He clearly wanted to make P3 (at that point), the concluding chapter to the trilogy. The execs obviously felt otherwise, and the lightning was left in to both "punch up" the ending "everybody hated" and leave an open door for a "Poltergeist IV." The decision to exclude Scott probably backfires, confusing the audience even more by his not returning. However, the budget has run out at this point, and "Scott" is not considered vital enough to the movie for the studio to go through the expense and complication of arranging another re-shoot with Kip present. The film is re-submitted to the MPAA for a re-rating the week of April 18, 1988. Apparently certain aspects of the new ending (the decomposed bodies, Kane's decapitation, Tom Skerritt's looping of "fucking sonofabitch!"in an earlier scene) earn the film the desired rating of PG-13. This is announced in the Monday April 25th, Bulletin # 1008.
23. The film is released June 10, 1988.
Now, to see how I went about my research, go here:
