A 14-year-old boy died Tuesday evening after crashing on an electric bike at the I-5 Colonnade mountain bike park, Seattle police said.

The teenager was riding down steep stairs at the mountain bike park underneath Interstate 5 in the Eastlake neighborhood when he lost control and fell, police said.

Seattle Fire Department crews arrived before police and tried to save the boy’s life, but he had died, police said. When officers responded after 6:15 p.m., they found that he had severe head and body injuries.

The boy was wearing a bike helmet, but he should have been wearing a motorcycle helmet, said police spokesperson Brian Pritchard. The electric bike had big tires and was more akin to a motorcycle.