IOWA CITY, Iowa (AP) – Authorities are investigating the cause of an accident that killed a boy on a popular boat ride at an Iowa amusement park, the second deadly incident on the ride in five years. Adventureland Park in Altoona, Iowa, says three other people are injured after the accident on the Raging River on Saturday night. The ride uses a conveyor belt to move rafts through faux river rapids. The injuries happened after a boat carrying six people flipped over. Altoona Police Department says 11-year-old Michael Jaramillo died Sunday of his injuries, and that another minor is in critical condition. A 68-year-old seasonal employee died on the same ride in 2016 after he became wedged between a boat and a concrete wall.