Updated

Part of a Fourth of July fireworks crowd overloaded a pedestrian bridge to about twice its capacity before it collapsed and sent about 50 people tumbling into a lake, the township trustee in charge of the bridge said Sunday.

About 25 people were injured. None of the injuries were life-threatening and all victims were accounted for, Merrillville Police Chief Joseph Petruch said in a statement.

The wooden bridge suspended by cables at Hidden Lake Park in Merrillville, about 45 miles southeast of Chicago, collapsed around 10 p.m. as spectators were leaving a fireworks display.

The bridge can handle about 40 people at a time but as many as 80 were on it when it fell, said Ross Township Trustee John Rooda, who attended the fireworks show and was on the scene within a few minutes. The township operates the park.

"The problem is it was overloaded," Rooda said. "We say 20 (people), it would have handled 40, but it was probably twice that."

Merrillville police officers were stationed at either end of the 90-foot bridge to control the number of people, but the crowd "rushed" the officers, Rooda said.

Petruch's statement did not mention officers being rushed. The Associated Press left a message with the police department seeking comment on Rooda's remarks.

The police statement said a preliminary investigation showed structural failure caused the collapse.

Rooda said the bridge has been inspected regularly, although he could not say when the most recent inspection was. He said the bridge is closed to motor vehicles.

Witnesses described a chaotic scene, estimating the span was full of people before it fell. "We were walking across and everybody just stopped ... we heard two snaps, and we all went in the water," Seth Argullin, 29, of Merrillville, told the Post-Tribune of Merrillville.

"People were grasping and hanging onto the bridge itself," Robert Walker of Merrillville told The Times of Munster.

Ross Township Fire Service Lt. Phil Topor said injuries ranged from lacerations to broken bones.

Police estimated the crowd at the park at about 10,000 people.

Rooda said about 25 first responders, including firefighters, police, lifeguards and trained bystanders, came to the victims' aid immediately, some within half a minute.

"Luckily, we had the people on the scene. We always do, just in case. Most of the time, it's a waste of money, but it certainly wasn't last night," Rooda said Sunday.