JACKSONVILLE, Fla. While battling a large fire aboard a cargo ship at Blount Island, the Jacksonville Fire and Rescue Department said an explosion occurred, injuring firefighters, News 6 sister station News 4 Jax reports. According to Fire Chief Keith Powers, eight firefighters were injured in the explosion, and an additional firefighter was treated for heat exhaustion. During a news briefing at 10:15 p.m., Powers said the eight firefighters hurt in the blast were in stable condition. Its a tough situation and very dangerous -- thats one of the most dangerous situations firefighters encounter is when theyre in a ship fire, Powers said. Several firefighters have been injured after an explosion at a ship fire.