ALTOONA, Iowa — One person has died after being involved in this weekend’s accident on the Raging River ride at Adventureland Park, officials announced Sunday evening.

“Adventureland is saddened to learn of the passing of one Guest involved in the Raging River accident,” Adventureland Park said in a statement. “This investigation is ongoing and the ride remains closed.”

Four people were injured after their raft overturned on the Raging River around 7:30 p.m. Saturday, according to the Altoona Police Department. Three of the riders had initially suffered critical injuries and a fourth person suffered minor injuries. All four were hospitalized after the accident. The latest conditions of the other three people injured in the accident haven’t been released.

The Raging River sends riders on large rubber rafts through river rapids. Adventureland officials said the ride had just been inspected a day before the accident and was found to be in sound working order.

Back in 2016, an Adventureland Park employee was killed in an accident while working at the Raging River. Steve Booher was working as a ride assistant when he slipped and fell into the conveyor belt that drives the ride’s cars. He died four days later from head injuries sustained in the accident.