The tanker, identified as the Atlantic Asphalt, struck the American Heritage paddlewheel cruise boat while it appeared to be docked, according to video footage from the scene. The impact caused the cruise boat to list heavily into the water, with people seen in the river wearing life jackets or standing near the railing as the vessel tilted further.

The American Heritage is operated by American Cruise Lines. The much larger tanker hit the cruise boat on Friday afternoon, though the exact time was not immediately clear.

Lt. Stephanie C. Norwood of New Orleans Emergency Medical Services said all agencies are responding to the rescue efforts. Authorities did not immediately release information on whether there were any injuries or deaths.

The incident underscores the risks of heavy maritime traffic on the lower Mississippi, a working river that carries tens of millions of tons of cargo each year while also hosting a growing river cruise industry. New Orleans, a major port city, sees frequent passage of tankers, barges, and passenger vessels.

Rescue operations were ongoing Friday evening. This is a breaking news story and will be updated as more information becomes available.