MASON, Ohio (AP) — A man who was struck by a steel roller coaster at an Ohio theme park last week after he entered a restricted area to retrieve his lost keys has died from his injuries.

Arntanaro Nelson, 38, of Wilmington, entered a fenced area at Kings Island on Wednesday night, according to a statement issued by the park. He was found on the ground with a “critical injury” and died Friday at a hospital.

The Hamilton County coroner’s office has listed Nelson’s death as a “suspected accident,” but it remains under investigation. His death was announced Monday.

Nelson dropped his keys while riding the Banshee, an inverted roller coaster where the train dangles from the track, and then went into the restricted area and was struck by the coaster, according to Mason police. No other injuries were reported in the incident.

According to the park’s website, the Banshee is the world’s longest steel inverted roller coaster and reaches speeds of 68 mph (109 kph).

The roller coaster was shut down after the accident but reopened Saturday.

The park is in Mason, which is about 24 miles (38 kilometers) northeast of Cincinnati.