The search for missing Buffalo Police diver Craig E. Lehner in the Niagara River ended its fourth day Monday without success.
At a 4:30 p.m. briefing, Police Lt. Jeff Rinaldo said boats and dive teams found no trace of Lehner or his equipment.
Officers continued the search until sundown Monday, and plan to return Tuesday morning.
"Everybody's tired. Everybody's stressed. But as I've said, we've got a job to do," Rinaldo said. "We're going to do it.
"We have a responsibility to bring Craig home for his family and we're getting through it," he said.
Search teams have been looking for Lehner, 34, since Friday afternoon when he failed to surface from a training exercise with the Buffalo Police Underwater Recovery Team at the foot of West Ferry Street.
The U.S. Coast Guard said a cable connecting Lehner to his diving crew broke, leaving him stranded alone underwater.
Lehner, a nine-year veteran of the force and a full-time K-9 officer, is presumed dead.
— Robert Kirkham (@RobertKirkhamBN) October 16, 2017
Rinaldo said if Lehner is not found in the next day or two, police will discuss possible changes in tactics. Still, a search will go on in some form, he said.
"We will never stop looking for him," Rinaldo vowed.
Police Commissioner Daniel Derenda thanked businesses, law enforcement agencies and the public for their support. He asked the public to keep Lehner, his family and all law enforcement in their thoughts and prayers.
Law enforcement crews on 10 to 12 boats searched the river Monday, with aircraft from the State Police, the Erie County Sheriff's Office and Customs and Border Protection taking turns searching by air.
Two Army Corps of Engineers boats with side sonar joined the search efforts Monday and the Coast Guard has done modeling based on the river's swift current to help guide the search. The search will focus more toward the middle of the river, as well as on the Canadian side and downstream, police officials said.
Robotic cameras and divers are also part of the recovery effort.
With the Erie County Sheriff's helicopter scanning the river from overhead, Rinaldi said during a Monday afternoon news briefing the debris field on the bottom of the river, which extends more than 100 feet from shore, made even the sonar search "extremely complicated."
"They said that if this was a still body of a lake or the usual river flowing at 2 to 3 knots, they'd have this mapped out like Google," he added.
Rinaldi said that divers were pulled from the search Monday morning because underwater visibility was "zero to 1 foot" following Sunday's storm.
The search for the officer was suspended at 3:22 p.m. Sunday because of high winds that made it unsafe for divers and crews on search-and-rescue boats equipped with sonar. On Sunday, divers searched a new area of the river, extending from the foot of West Ferry north to the International Railway Bridge.