American Heritage capsized after the tanker Atlantic Asphalt struck her amidships on the Mississippi River in New Orleans on Friday, November 13.
Authorities accounted for everyone aboard both vessels. Officials reported no deaths or critical injuries.
The U.S. Coast Guard and National Transportation Safety Board are investigating. They have not established the cause.
What happened on the Mississippi River
Atlantic Asphalt struck the docked American Heritage at about 12:30 p.m. local time, near the Port of New Orleans.
The riverboat had arrived roughly two hours earlier. Passengers were disembarking when the tanker hit.
The American Heritage began listing within minutes, then rolled onto its side and became partially submerged. Videos and witness accounts indicate the tanker struck the riverboat amidships.
Vessel details and passenger numbers
American Cruise Lines operates the American Heritage, a riverboat built in 2015 with capacity for 150 passengers.
Atlantic Asphalt is an asphalt and bitumen carrier sailing under the Marshall Islands flag. Its IMO number is 9798428.
Early reports cited about 129 passengers aboard the American Heritage. Later estimates placed the total number aboard, including crew, between 180 and 190.
Rescue and injuries
Port employees, tugboat crews, police, firefighters and other responders rushed to help. Nearby vessels pulled people from the water.
Officials said 87 people left the riverboat before it capsized. Rescuers took about 30 to 45 minutes to reach those remaining in the water.
Officials reported 32 hospitalisations: 30 passengers and two Harbour Police officers. They described the injuries as non-critical.
Cause remains unconfirmed
Coast Guard Captain Melanie Burnham said the tanker appeared to suffer some loss of steering. She stressed that investigators did not yet know the exact cause.
That steering problem remains a preliminary indication, not a confirmed finding. Investigators have not announced a probable cause.
The Coast Guard is investigating and plans to convene a Marine Board of Investigation, according to reporting that cited a Coast Guard official. The NTSB also planned to send investigators to New Orleans.
The agencies have not published final findings. Therefore, the circumstances behind the allision remain under investigation.