Two fuel barges exploded on Alabama's Mobile River Wednesday night, critically injuring three and causing a large blaze which raged for many hours.
Reuters reported the massive blast forced authorities to evacuate nearby shipyards and a cruise vessel.
But after a long and difficult night in which further explosions occurred, the fire was extinguished Thursday morning, Mobile Fire-Rescue spokesman Steve Huffman confirmed in a statement to AP.
He said the explosion appeared to be accidental but investigations were continuing.
Authorities said three people suffered serious burns and were taken to University of South Alabama Medical Center. Their conditions remain critical.
Witness Alan Waugh, the general manager at the Ft. Conde Inn, who is based half a mile across the river said the explosion sounded "like planes above you dropping bombs".
"We were up on a second floor balcony and the sky lit up in orange and yellow," he told CNN affiliate WALA TV.