At least 25 people were taken to local hospitals, eight were treated on site and additional guests may have left injured when a section of the structure gave out at Briarwood Country Club in Billings, Mont.

More than 30 people were injured when the second-story patio floor of Briarwood Country Club in Billings, Mont. broke and gave way July 22. At least 25 people were taken to local hospitals, eight were treated on site and additional guests may have left injured, Billings Police Lt. Matt Lennick said in the statement.

The collapse caused head wounds, broken ribs and other injuries as people landed atop each other and debris and scraps of food scattered over the grass next to the club’s golf course, The Billings Gazette reported. The cause of the collapse has yet to be determined.

Mark Zagel, a Briarwood patron who fell through the deck, wrote on Facebook that there were between 30 and 40 people on the patio when a section collapsed about 12 or 13 feet, without anyone directly below.

“I am fine though the ribs on my right side are pretty bruised and have a couple of other minor bumps. Nothing broken, no head injuries … There were multiple other more significant injuries — mostly broken bones,” he said. “I landed on someone directly and had to be helped off her.”