Panic Room

Starring Jodie Foster and Kristen Stewart, this thriller involves an invasion of their home that turns violent. Its opening weekend grossed nearly $30 million and resulted in the nomination of Foster for a Saturn Award for Best Actress.

In a last-ditch effort to create a diversion and escape their home, Foster lights a propane tank and then drops to the floor, attempting to crawl out.  Unfortunately, this would never happen–propane is not lighter than air.