El Faro, the 790-foot cargo ship that went missing at sea in the path of Hurricane Joaquin, likely sank, the a Coast Guard official said Monday.

“For our search planning efforts, we are assuming that the vessel has sunk,” Capt. Mark Fedor said at a news conference. “We are searching for any signs of life for that vessel.”

The ship and the 33 people on board have been missing for four days.

Search crews spotted life rings, debris and an oil slick near El Faro’s last known location, 35 nautical miles northeast of the Crooked Island in the Bahamas — but for days, there were no signs of the ship or survivors.

Fedor said Monday that human remains were found in at least one survival suit. A helicopter crew, he said, had to leave the body behind to search for possible survivors.

An empty lifeboat “with markings consistent with those on board the El Faro” was also located by search teams. The lifeboat was heavily damaged, according to the Coast Guard.

Tim Nolan, president of the ship’s owner, TOTE Maritime Puerto Rico, said in a statement Monday that the company “is distressed that it now appears the El Faro sank at or near its last known position.”

“We continue to hold out hope for survivors,” Nolan said. “Our prayers and thoughts go out to the family members and we will continue to do all we can to support them.”

Of the 33-member crew, 28 are American and five are Polish.

“We’ve been going with no sleep for four days,” Laurie Bobillot, whose daughter Danielle Randolph was aboard the ship, told The Washington Post on Sunday night from Jacksonville, Fla., where she and other family members of the crew gathered.

The Coast Guard’s search for the vessel began Friday during unfavorable, hurricane-like conditions, Fedor said. It wasn’t until Sunday that Coast Guard vessels and aircrafts were able to search without high winds and with good visibility.

The El Faro went missing in 15,000 feet of water while a Category 4 storm packing more than 140-mile-an-hour winds was “sitting right over it,” Fedor said.

The ship was equipped with more than enough life suits for the crewmembers on board and two lifeboats that could carry 43 people. Several suits have been spotted in the water, and one of the lifeboats was identified with no signs of survivors aboard.

“We remain hopeful that we will try and we will hopefully find survivors,” Fedor said. “That is our focus as we move forward.”

The ship departed Jacksonville, Fl. on Tuesday and was expected to arrive in San Juan, Puerto Rico on Friday. The company said in a statement that the officers and crew were monitoring the storm.

“Not sure if you’ve been following the weather at all,” Randolph wrote in an e-mail to her mother on Thursday, “but there is a hurricane out here and we are heading straight into it.”

Just hours after Randolph sent her e-mail, El Faro began to take on water and tilt to one side, according to TOTE Maritime. Then the ship’s communications suddenly went quiet.

It hasn’t been heard from since.

This post has been updated.