Investigators continue looking for the cause of an accident that left a child dead after an accident Saturday night at a central Iowa amusement park.

A news release from the Altoona Police Department says a raft carrying six passengers on the Raging River ride at Adventureland overturned. The child who died is identified as 11-year-old Michael Jaramillo. Police say three other riders were taken to hospitals in critical condition while a fourth had minor injuries.

The cause of the accident is under investigation. Five years ago, an Adventureland staff member was killed at the same ride after a fall. State OSHA fined the park $4,500 after that incident.

Reports say the ride, which is now closed, passed an inspection last Friday.