Video Emerges of Raft Flip That Killed 11-Year-Old Boy at Iowa Amusement Park

The footage, obtained by GMA, was shot by fellow Raging River riders who were following on the raft behind.

"Oh they flipped! Holy s--t they flipped," the man filming on his cellphone can be heard shouting. "Are they okay?"

"Watch out guys, watch out! Watch out!" the female passengers yell at the parents as they approach, apparently worried that the most impending danger is an accidental collision.

Warning: Distressing footage

But the alarm in their voices quickly rises as they pass the overturned craft and they hear the distressed cries of the couple desperately trying to free their children trapped underneath.

"Oh my God! What do we do? What do we do?" they ask each other. "I can't stop!"

The boys' father David tried to lift the craft but couldn't, having broken his shoulder in the crash.

"I'm looking around for anybody to help us, I'm saying 'Help! Our children are drowning!'" he said.

"You could see the kids' little hands, and they were just trying to reach for us to help them, and I was trying...it was so bad, I didn't know what to do, they were drowning upside-down."

An 11-year-old boy is dead and his 15-year-old brother has been left in a coma after an accident on a water ride at an Iowa amusement park.

Michael Jaramillo and his big brother David were aboard the Raging River at Adventureland Park in Des Moines on Saturday when their raft flipped over, trapping them beneath.

The siblings had boarded the ride along with their parents, little brother Gus, and cousin Mila. The other four managed to escape, but the two brothers could not free themselves from their seatbelts, and were pinned underwater.

The force of the water on the ride prevented their father David from desperately trying to save them.

"I'm drowning," he told GMA from the hospital Tuesday morning. "The river was so intense, it was like a suction."

"I see the silhouettes of my sons trying to grab each other, grab us," he said. "They want us to help them. We couldn't do it."

Bystanders jumped in to pull the other two children from the water. The brothers were eventually freed from the ride and were rushed to hospital. However Michael succumbed to his injuries the following day, while David is still fighting for his life in a medically induced coma.

"He was a baby and I feel like Adventureland robbed me of my baby," his mother Sabrina sobbed. "I will never get a chance to see him grow up or get a chance to see him graduate."

"He was just taken from us," her husband added. "Love your kids. You just don't know when they'll be taken."

David turns 16 on Wednesday; the family had been at the park to celebrate his upcoming birthday.

A spokesperson for the family-owned park said it was saddened at the death of a guest, adding that the ride has been closed for an investigation.

"The Raging River ride has been in operation for nearly four decades," attorney Guy R. Cook told ABC News, adding: "It is a safe ride."

"The ride was inspected by the State of Iowa the day before the incident and was in good working order."

The Raging River, which first opened in 1983, buckles riders into large circular rafts which then cascade through a course of rapids.

Saturday's was not its first fatality either; in 2016 Adventureland employee Steve Booher, 68, was killed while helping guests exit the ride, when the conveyor belt suddenly started moving.

He became trapped between the belt and the wall, crushing him. He died four days later in hospital, with cause of death listed as brain trauma.

His wife later sued and settled for an undisclosed sum out of court. The park was fined $4,500 by Iowa's Occupational Safety and Health Administration, but allowed to keep the ride in operation.