Before post-production was completed on Poltergeist III, the horror trilogy's child star Heather O'Rourke died on February 1988 from a cardiac arrest caused by septic shock brought on by the intestinal stenosis.
Heather O'Rourke, a beautiful little girl. (December 1975 – February star of the Poltergeist movies. She died at the age of 12 of cardiac arrest and septic shock caused by a misdiagnosed intestinal stenosis.
Celebs Who Died While Filming A Movie Or TV Show, Part 2