Littleton fire rescue were called out to a home in the 7600 block of West Ottawa Place around 9:30 p.m.
The Denver Post reports that 10 to 15 adults were on the deck when it collapsed at a backyard party Tuesday night. Roland Seno of Littleton Fire Rescue said the deck collapsed diagonally into the home.
A Littleton building inspector was called to the home, and firefighters stabilized the deck before leaving the home.
Four people were hospitalized. Their names and injuries weren't immediately released.
Associated Press contributed to this report