One person is dead and two others missing after a pontoon boat believed to be carrying 19 people sank near Alcatraz Island in San Francisco Bay on Tuesday. Another 16 people have been rescued, the fire department said. Authorities told the San Francisco Chronicle it appears an explosion took place onboard. San Francisco firefighters and the U.S. Coast Guard began responding to the incident around 3:30 p.m. The Coast Guard initially described the incident as a “vessel fire,” though the fire department later said it did not encounter evidence of a fire on the vessel or among survivors. “Search and rescue efforts are ongoing, and a triage area has been established ashore,” the Coast Guard wrote in a statement on X. The maroon and white boat sinking beneath the waves. This is a breaking news story and will be updated with new information.