Contis bakery is actually a real location and was the inspiration for the story although the characters themselves are made up. The bakery is in the Morris Park section of the Bronx and has been in business since 1921.
The film was shot in a heatwave and there were no air conditioners on set. One crew member recorded the temperatures rise to 120 degrees which lead to some grueling conditions. This was subsequently written into the radio announcer dialogue.
The trivia item below may give away important plot points.
The effects in the end scene were done with some clever manipulations. Films props were burnt and destroyed. Walls were wiped with black ash, insulation was throw about, and a garden hose was run though the ceiling with holes cut in it to simulate leaking water from the destruction. The entire setup and cleanup of the final scene took 3 days.