UPDATE, 10:20 P.M.: Rescue workers found an additional two bodies on Tuesday, bringing the confirmed death toll to 16. In addition, they believe they may have found another eight bodies, but those have not been located and confirmed yet.

The prognosis looked increasingly bleak as rescue workers entered their fourth day of searching the massive field of debris left behind by the landslide in Washington state. Authorities stressed that they still considered this a rescue effort as well as a recovery, even as they acknowledged the grim reality of the mounting death toll, the long list of people reported missing and the days that have passed since a survivor was found.

Two key numbers remained the same from Monday night and well into Tuesday: The death toll remained at 14 on Tuesday morning, a number expected to increase during the day; 176 names were still on the list of people reported missing, a number expected to go down.

Additional victims of the slide were found at the site on Tuesday, but the exact number has not been confirmed, the Snohomish County Sheriff’s Office said Tuesday afternoon.

“I’m very disappointed to tell you that we didn’t find any sign of any survivor, and we didn’t find any survivors today,” Travis Hots, the Snohomish County District 21 fire chief, said in a news conference Monday evening. On Tuesday morning, Hots said at a news conference that no surivors were found overnight.

The slide on Saturday spanned a one-square-mile area near Oso, Wash., about an hour north of Seattle. The field of debris, which is 15 feet deep in some spots, is very difficult for rescue workers to navigate. It’s “like quicksand” in some areas, Hots said.

Other complications have hampered the rescue efforts. On Monday, some rescue crews were pulled out for a few hours due to fears that additional slides were possible before the area was confirmed to be stable, said Steve Thomsen, the county’s public works director. Tuesday brought rain, which was expected to continue for days and which could make it more challenging for workers on the ground and for helicopters, Hots said.

A volunteer rescue worker suffered minor injuries working in the  landslide area when a small bit of debris, kicked up by a helicopter’s wash, hit him in the head, the county said Tuesday afternoon. He was taken to a nearby hospital.

The U.S. Geological Survey said that the landslide was caused by recent rain that had saturated the soil. Debris from the landslide covered nearly a full mile of State Route 530 and caused a blockage on the North Fork of the Stillaguamish River, creating a flood hazard, the USGS said. The U​SGS and the National Weather Service are trying to determine what would happen if the blockage broke and where flooding could occur.

A flash flood watch was in effect for Snohomish County through Tuesday afternoon, which means that flooding could occur but isn’t imminent, the National Weather Service said. Still, it urged people to avoid the river’s North Fork.

There are 156 people working in the field trying to find survivors or bodies, Hots said, and a National Guard team arriving Tuesday will add another 50 to those ranks. The rescue effort also includes dogs, infrared technology and helicopters. The area is being monitored for additional landslide risks.

Rescuers have not found anyone alive in the debris since Saturday, the day the landslide hit.

“We’re going to be very candid,” said John Pennington, director of emergency management for the county. “It’s been a number of days. We requested a mortuary team to assist with this process, [which] speaks for itself.”

But authorities said they were still hoping to find additional survivors and to recover bodies.

“We are going to do everything that we can with our capabilities to recover every single person,” said Hots, who added that this effort could take weeks. “That’s no guarantee that we’re going to get everybody, but we are going to do our very best to get everybody out of there.”

President Obama, speaking at the Nuclear Security Summit in the Netherlands on Tuesday, said he spoke with Washington Gov. Jay Inslee and has signed an emergency disaster declaration.

“I would just ask all Americans to send their thoughts and prayers to Washington state and the community of Oso and the families and friends of those who continue to be missing,” the president said. “We hope for the best, but we recognize that this is a tough situation.”