A group of current and former firefighters and their children had just attended a parade as part of the 142nd annual New Jersey State Firemen's Convention & Memorial Service.
They were gathered at a three-story home on East Baker Avenue Saturday night when the upper deck gave way, pancaking those below, responders said.
Most of those hospitalized were released after being treated, according to Cape Regional Health System.
A victim who was airlifted to Atlantic City Medical Center's Trauma Unit and another who was taken by ambulance remained hospitalized, authorities said.
A witness told CBS3 that neighbors rescued a 2-year-old girl.
SEE: Wildwood Crest Deck Collapse
DAILY VOICE PHOTOS: No re-use without permission
“We were sitting up on [our] deck and watched the whole thing happen. It was horrible,” witness Gail Ivins said. “There were people — they weren’t dancing or anything. They were sitting, a bunch of people. There were children on the decks — all three levels.
“We heard the noise of it starting to pull away. The first-floor deck pulled away first. People started sliding off and yelling, falling. Then as that went, it pulled the pillars down and the third-floor deck came down. It was very slow motion. It was really scary. It came off in pieces."
A pole was put in place to support the building's hip-roof, which hung over the wreckage.
DAILY VOICE PHOTOS: No re-use without permission
Click here to follow Daily Voice Jersey City and receive free news updates.