This story was updated at 10:20 p.m. EDT.

A second body was recovered in the Hudson River on Sunday a day after a tugboat collided with a barge and sank at the Tappan Zee Bridge, where a new span north of New York City is under construction, authorities said.

The body of Timothy Conklin, 29, of Westbury, New York, was pulled from the river.

A third person aboard the boat, Henry Hernandez, 56, remains missing, and divers were searching for him in conditions that New York Gov. Andrew Cuomo described as "very difficult" because of the poor visibility. Crewman Paul Amon, 52, was also killed in the accident.

"Much of the diving operation is actually done by feel," Cuomo said at a press conference. "The ship itself is damaged, which makes the investigation of the interior more problematic."

The pre-dawn accident on Saturday involved a 90-foot tug that struck a construction barge moored at the base of the Tappan Zee Bridge, a major thoroughfare connecting the suburban Westchester and Rockland counties.

Cuomo, who said the incident appeared to have been "a pure accident," said state authorities were working to contain an oil slick created by the leaking of thousands of gallons of diesel fuel from the sunken tug. There was an estimated 5,000 gallons of fuel on board.

The barge is one of several moored near the bridge as part of a project to construct a new replacement span. Cuomo said on Saturday that 21 workers on board the barge were not injured in the accident.

The tugboat, called Specialist, was one of three transporting a barge with construction equipment. The other two boats were not involved in the crash.

The bridge project was the site of another deadly accident in July 2013, when a speedboat carrying six members of a wedding party smashed into a barge anchored beneath the span. Two people were killed, including the bride-to-be and the best man.