NEWARK, N.J. (AP) — A cargo ship docked at the East Coast's biggest port smoldered for a third day and will likely burn for several more after the fire claimed the lives of two New Jersey firefighters, officials said Friday, acknowledging that they'll be discussing how first responders are trained.

What caused the fire aboard the Grande Costa d'Avorio, an Italian-flagged vessel carrying cars and other goods, at port in Newark won't be known until an investigation after the fire is out, according to Coast Guard Capt. Zeita Merchant, the captain of the Port of New York and New Jersey.

A crew of 20 firefighters, salvage workers and a New York fire boat blasted jets of water onto the ship to contain the intense heat, which officials have said burned on the 10th through 12th levels at the rear of the ship. Flames occasionally flared from top level.

Crews described the difficulty controlling the blaze.

“Access is tough. The heat is extreme. It’s a steel box. So it’s a very complex situation,” said Gordon Lorenson of Donjon Marine, a salvage company assisting with the fire.

Fire crews have to pour enough water onto the vessel to douse the flames but too much could cause the ship to tilt, he said, so they then pump it off the ship. The vessel listed slightly to its right but was stable, according to Tom Wiker, president of Gallagher Marine Systems, which was representing the ship's owner, the Grimaldi Group.

The Port Authority relies on local fire departments, like Newark’s, to assist with fires since it doesn’t have its own firefighting agency.

Authorities declined to answer whether firefighters should have gone into harm's way to put the blaze out when no lives appeared to be at risk on the ship with 28 crew members.

Newark Public Safety Director Fritz Frage said the city has an agreement with the Port Authority of New York and New Jersey covering their response to fires and they continue to have conversations “today and going forward in terms of training.” He didn't offer specifics about training.

Lorenson said shipboard fires are unique from one event to the next and can change.

"You can do all the training in the world and you’re going to find something you’ve never seen before,” he said.

Newark Fire Chief Rufus Jackson said Thursday that the department had trained on passenger-carrying ships before, but not the specific kind of cargo vessel they’re confronting now.

Killed in the blaze that started Wednesday night were Newark firefighters Augusto “Augie” Acabou and Wayne “Bear” Brooks Jr., whom officials praised for their bravery. President Joe Biden called the families of the fallen firefighters to offer condolences, according to Michael Giunta, head of the firefighters union.

At a memorial Friday, the men were remembered by friends and family, speaking through tears.

Roger Terry, Brooks’ uncle, called his nephew “a real-life Superman” who had always wanted to be a firefighter. Brooks’ wife and two daughters sobbed as he was remembered.

Firefighter Michael Johnson of Ladder 4 said Brooks “loved his life, loved his kids. He loved the job more than anything. ”

Acabou’s cousin, Newark fire Capt. Carlos Henriques, read a letter from his family about Acabou, calling their loss “unfathomable.”

Acabou’s “sense of honor was unparalleled. And he consistently exemplified this through his actions. Everything he did was about helping others, going above and beyond for those in need.”

Marine traffic trackers show the ship, which was was built in 2011, had arrived from the Port of Baltimore several days earlier. It was carrying more than 1,200 new and used cars, vans and trucks.

The fire broke out about 9:30 p.m. Wednesday. About an hour later, there was a mayday call when two firefighters became trapped inside the ship. Rescue workers rescued Acabou from the ship before midnight and he was later taken a hospital, where he died Thursday morning. Brooks died early Thursday morning after he was recovered. Five other firefighters were injured.

Grimaldi Deep Sea said in a statement that the crew immediately activated on-board fire suppression procedures and the local firefighting service was alerted, triggering a prompt response that was crucial to containing and controlling the blaze. It also said that no electric cars nor hazardous cargo is on board, no fuel spills have been detected, and the stability of the ship was not been compromised.

The Grimaldi Group statement said the cause of the fire isn’t known, but it will investigate in cooperation with authorities.

A 2020 inferno aboard a U.S. Navy ship in San Diego reflects the challenge of containing fires aboard vessels. In that case, the USS Bonhomme Richard, a $1.2 billion amphibious assault ship, burned for nearly five days and eventually had to be scuttled.