A search was underway for a missing tugboat crew member after three others were rescued Saturday when their boat sank in icy and stormy waters about a mile off Fire Island on New York's Long Island, authorities said.

One of the crew members managed to make a cellphone call to the Coast Guard at about 2 p.m. as the tugboat Sea Bear was sinking, said Coast Guard Petty Officer Morgan Gallapis.

She said the man said their boat was sinking and they needed assistance.

"They had only seconds to let us know before they sank," Gallapis said.

Three male crew members in immersion suits were rescued by the Coast Guard from the water a mile off a section of Fire Island known as the Pines, Gallapis said.

But another man was missing as a search continued by three Coast Guard boats, a helicopter, two other tugboats and Suffolk County Police Marine Bureau boats, authorities said. Suffolk officers on the beach assisted in the search.

Gallapis, based in the New Haven, Connecticut Coast Guard station, said the three men who were rescued were treated for hypothermia at the Fire Island Coast Guard station but otherwise had no physical injuries.

She did not know what caused the boat to sink.

The accident occurred during a storm. Suffolk County police said inclement weather prevented their aviation officers from flying and police Marine Bureau boats were hampered by heavy ice in the water.

The petty officer said the tugboat that sank was among three heading back to their New York City base after completing a project on Long Island.

"This tug was in the back of the line when it sank," she said. "The other tugs continued without seeing them. They heard the distress call and headed back to assist in the search."