PEORIA, Ariz. - A 50-year-old man suffered burns on 70 percent of his body after a boat exploded at Lake Pleasant Sunday, Peoria fire said.

According to Peoria fire, there was a flash explosion at the Scorpion Bay fuel dock. The fire "immediately" burned two people.

The 50-year-old man was airlifted to a hospital in critical condition while the other person suffered burns but refused to be taken to a hospital, Peoria fire said.

Peoria fire said two other people were at the marina during the explosion and were treated for smoke inhalation.

According to Peoria fire, the flames were quickly extinguished but the boat was destroyed.

It's unclear whether fueling was in progress when the incident happened.

The cause of the explosion is under investigation.