UPDATE: 12 p.m.: The US Coast Guard says it appears fire started when a spark somehow entered into barge tank.
USCG and Mobile Fire-Rescue are conducting the investigation and taking pictures.
There is no danger to the public.
Once they're finished gathering evidence, the barges should be towed to shipyard to decide if they will be salvaged, scrapped or repaired.
UPDATE: Thursday 11:00 a.m.: The fires caused by multiple explosions on the Mobile River Wednesday night are now out. According to officials, the area is secured.
Investigators are still trying to determine the cause of the explosion.
Around 8:30 p.m. Wednesday night, two empty unmanned tank barges owned by Kirby Inland Marine, LP were being cleaned at Oil Recovery Company and caught fire and exploded. The barges had been turned over to the shipyard and were in its custody when the incident occurred.
Three individuals were injured and taken to USA Medical Center where they are suffering from severe burns. None of the injured are employees with Kirby Inland Marine, LP.
Several explosions happened on two barges on the Mobile River Wednesday night.
Mobile Fire and Rescue responded to the east side of the river after the initial explosion happened around 8:30 p.m. As of about 2:30 a.m. there were a total of seven explosions on the barges.
The barges had previously been loaded with gasoline when the explosions occurred. The explosions could be heard in Summerdale, Bay Minette, Spanish Fort, Saraland, and Satsuma. Some people have reported shaking windows and doors at their homes due to the explosion.
Steve Huffman with Mobile Fire and Rescue has told News 5 that three people were injured in the explosion. They have been taken to the USA Medical Center where they remain in critical condition.
Responders are planning to let the barges continue to burn for the rest of the evening.
The explosion comes two months after a Carnival cruise ship was towed to Mobile after becoming disabled during a February cruise by an engine room fire. The ship is still undergoing repairs there.