PATCHOGUE - The Suffolk Marine Unit, the Coast Guard and several fire departments responded to a multiple-boat fire on the Patchogue River today.

Chopper 12 was over the scene at a 60-boat marina after fire officials received a call at around 1:30 p.m. about a single-boat fire. Shortly after, witnesses reported hearing an explosion as flames began to spread.

Arson investigators are trying to figure out what caused the initial fire. According to police, someone was working on a 40-foot boat on the north dock when it suddenly caught fire and exploded.

Firefighters were able to extinguish the fire in less than an hour, but damage to the boats was already irreparable. Officials have not confirmed any injuries, but at least two people were taken into an ambulance with breathing problems.

To watch Chopper 12 footage of the fire, tune to channel 612 on your iO digital cable box and select iO Extra.