Fires aboard two fuel barges in Alabama's Mobile River that left three people critically injured after a fireball and several explosions lit the night sky have been allowed to naturally burn out.
Fire and rescue crews with the Coast Guard were responding to two explosions and a fire at the natural gas barges when a third explosion occurred on Wednesday night.
A fourth explosion was then reported just before 10pm local time.
SCROLL DOWN FOR VIDEO
Dangerous: Four explosions took place on two barges on the Mobile River in Alabama at around 10pm Wednesday night, injuring three people
Flammable: The barges used to hold compressed natural gas but was empty at the time
Three people were hospitalized with burns, but specific information on their conditions was not immediately available. Later in the evening, the local Fox affiliate reported that the three injured individuals were in critical condition. They have not been identified.
The Coast Guard reports that they received their first notification of the first explosion at 8.40pm, and the second at 9.10pm.
More...
President Obama orders flags to be flown at half mast as he arrives in Texas to witness devastation caused by fertilizer plant explosion that killed 14 people
Brave victim who horrific injuries she suffered at Texas fertilizer plant blast says 'it is another bump in the road for me'
The barge was empty but filled with vapors from compressed natural gas it typically carries. It was being held at the Mobile Bay ship channel for cleaning at the time.
Lt Mike Clausen told Fox10TV that a spark entered the barge igniting the vapors with that first explosion causing the second barge to catch fire.
They are still trying to determine where the spark originated. The fires were allowed to burn out on their own, leaving the barge that exploded stable but extremely damaged according to Clausen.
VIDEO Watch as the terrifying explosions are caught on camera...
Fuel barge explosions caught on camera. WARNING Loud noise
Serious: The three people who were injured, who remain unidentified, were all listed in critical condition
Cordoned off: The Coast Guard implemented a protective area of one nautical mile around the barges
Throughout the night officials established a safety zone of one nautical mile around the barge as a number of emergency service crews responded to the scene.
Among them were 25-foot and 45-foot response boat crews, ships from Coast Guard station Dauphin Island and state, local, and federal authorities.
Fire officials said they planned to let the barges burn into the night because the situation was too unstable. Pictures captured by local photographer Dan Anderson show that the flames are rising high in the air about the barges.
The Carnival Triumph, the cruise shop that became disabled in the Gulf of Mexico last February before it was towed to Mobile's port, was evacuated as it was being repaired nearby.
The explosions happened in an area of the river east of downtown Mobile, Mobile Fire and Rescue spokesman Steve Huffman said.
U.S. Coast Guard Petty Officer Carlos Vega said the initial blast took place in a ship channel near the George C. Wallace Tunnel - which carries traffic from Interstate 10 under the Mobile River.
The spark: The cause of the fire remains unknown but the police plan to let the flames burn into the night because they feel the situation is too unstable
Fire on the water: Aside from the three critically injured individuals, the fire is not thought to be any threat
The explosions rattled the windows of houses in downtown, blew doors open in the Spanish Fort area and aftershocks were reported in Bay Minette and Fort Morgan, the Mobile Press-Register reported.
Video from WALA-TV shows flames engulfing a large section of the barge.
Coast Guard officials were heading to the scene and the cause of the explosion was not immediately clear, Vega said.
The explosion comes two months after the 900-foot-long Triumph was towed to Mobile after becoming disabled during a cruise by an engine room fire, leaving thousands of passengers to endure cold food, unsanitary conditions and power outages.
Getting fixed: The infamous Carnival Triumph, seen here being towed back to shore after getting stuck at sea in February, was near the explosion as it was on the Mobile River getting fixed
The ship is still undergoing repairs there.
Earlier this month, the 'cursed' boat was dislodged from its mooring by a windstorm that also caused two shipyard workers to fall into Mobile Bay.
While one worker was rescued, the other body was pulled from the water more than a week later.