Police officers searched the Hackensack River and its banks on Tuesday for the body of an officer believed to have died when his vehicle plunged off an open drawbridge in heavy rain and fog.

The body of one officer, Shawn Carson, was recovered shortly after the accident Christmas night, and authorities resumed the search Tuesday for Officer Robert Nguyen.

Boats and sonar were being used in the search, which had been expanded to 1 mile in either direction from the bridge, police said.

Swift current prevented divers from returning to the water, where visibility was limited.

"They were feeling around with their hands down there," Kearny police Sgt. John Manley said.

The officers had crossed the Lincoln Highway Bridge from Jersey City to Kearny to place warning cones and flares, because the safety bar and bell used to warn motorists when the bridge is open were out of order, said police Chief Robert Troy.

Before the officers turned around and drove back across the bridge, its operator raised the middle span to allow a tug boat to pass underneath. The police officers' vehicle went off the open end of the span and plunged about 45 feet into the frigid water.

"As dark as it was, as foggy as it was, as rainy as it was, they had no idea," Troy said.

The bridge's warning system had been damaged by a truck two days earlier, officials said.

Carson, 40, was pronounced dead at University Hospital in Newark. Troy said he believed the impact of the truck hitting the water killed the 16-year veteran of the force.

"The members of our department are heartbroken," he said.

Nguyen, 30, had been with the police department for six years.

"He could be anywhere, depending on the tides," said Officer Juan Bonet. "We just want to bring him home."

Mayor Jerramiah Healy said he knew both men and called them "uplifting, terrific cops."

"The horrible irony is they were responding to the very situation that caused their demise," the mayor said. "The bridge operator wanted cones and flares and our police department was the first to respond."

The Lincoln Highway Bridge is one of about 10 "lift bridges" on the river that date back to the early 20th century. It is an "on demand bridge," meaning operators respond to requests from boat pilots rather than follow a set opening schedule.

Investigators were still trying to determine whether the bridge operator was required to contact Carson and Nguyen that the bridge span was being raised, or if the officers should have notified the operator before they crossed back to the Jersey City side, said Erin Phalon, a department of transportation spokeswoman.

"Everything in the universe that could have gone wrong, did go wrong," Lt. Tom Comey said.