(CNN) — At least 16 people were injured when a pedestrian bridge collapsed into a lake after a July Fourth fireworks show Saturday night in Merrillville, Indiana, authorities said.

“It could not have happened at a worse time,” said Ross Township Fire Marshall Mike Sneiderwine. “The show was over and people were leaving. There were about 100 people on the bridge at the time, and lots of them ended up in the water.” The accident occurred at Hidden Lake Park.

As helicopter crews helped search the lake, dive teams rescued the adults and children who had fallen in, authorities said. The lake is about 7 feet deep.

“There was massive screaming,” said Michael Moses, who was on the bridge with his two children. “It was a terrifying situation.”

Moses and his children fell into the water, but none was injured.

Most of the injuries were not life-threatening, authorities said. One person suffered a broken leg. Others had twisted ankles, scrapes and bruises.