(CNN) - At least 22 people were injured Saturday evening when a multilevel deck collapsed at a condo building in Wildwood, New Jersey, trapping multiple people in the wreckage, according to the city's fire department.
The collapse happened at a seven-unit condominium on East Baker Avenue, according to a press release from Wildwood Fire Chief Daniel Speigel.
"The 2nd and 3rd floor front decks suffered a complete 'pancake' type collapse trapping multiple people," Spiegel said in the release.
The trapped people were extricated and taken to hospitals in about one hour, Speigel said. Video from CNN affiliate WPVI showed the deck's wreckage in front of a building not far from the ocean.
One of the injured was airlifted from the scene to AtlantiCare Regional Medical Center in Atlantic City, Speigel said. That person remains hospitalized, according to the hospital.
Twenty-one of the injured were taken to Cape Regional Medical Center in Cape May, said hospital spokeswoman Susan Staeger. Of those, 19 were treated and released by 11:30 p.m. Saturday, Staeger told CNN on Sunday. The remaining two patients were transferred to trauma centers. The discharged patients included three children, Staeger said.
Wildwood is a city of about 5,000 people on the South Jersey coast. It is the site of the yearly convention of the New Jersey State Firemen's Association. The convention started on Saturday, according to the association's website.
The Sussex County Fire Chiefs Association posted on Facebook that between six and eight members from Branchville and their family members were on the second-floor deck when the top deck collapsed. They were treated for injuries, none of which were life-threatening, the post said.
The association updated its post to say that all but one person from Sussex County was released from the hospital Saturday evening.
The Wildwood Fire Department and the city's construction office are "working with the building owners, engineers and contractors to properly secure a hip-roof that is currently unsupported due to the collapse," said the fire department's press release.