One man died Saturday morning after an explosion on a boat docked on the Hudson River in New York, authorities said.

The man was doing work involving a flame or sparks when the blast happened about 10:30 a.m., the U.S. Coast Guard said on social media.

First responders answering a 911 call found a 59-year-old man unconscious in the river, and he was declared dead at the scene, New York police said.

Authorities are still investigating the cause of the explosion, police said.

The man's name was not released.