Two firefighters died Thursday when the wall of Weaver Organ and Piano building in York, Pennsylvania, collapsed. The coroner identified the men as Zachary Anthony, 29, and Ivan Flanscha, 50.

The York firefighters were trying to put out the hotspots on the burning building on North Broad and Walnut Streets at 4 p.m. EDT when a chunk of the factory collapsed and four men were trapped underneath the debris.

They were rescued and rushed to the York Hospital, where two of them were pronounced dead.

"We are terribly saddened for the loss suffered by the family, friends, and fellow firefighters of Ivan and Zachary. This marks a tragic day in York's history,” York Mayor Michael Helfrich said, NBC affiliate WGAL reported. "York City Residents will forever be grateful for the years of service that Ivan and Zachary gave to us to protect our lives and families.”

Anthony joined the York City Fire Department in August 2010. A fire official described him as a “fun-loving guy,” and added “he was awesome.”

Flanscha, on the other hand, was a decorated veteran who had served 20 years in the department. He was the recipient of several meritorious accolades such as "Firefighter of the Year" award and the Chief's Commendations award.

Anthony and Flanscha became the 12th and 13th firefighters to die on duty in the York fire department. Prior to the latest incident, the last firefighter to have died from the department on duty was back in 1971.

"This is the worst day in my career, this is the worst day for the York City Fire Department," Fire Chief David Michaels said, local newspaper York Daily Record reported. "We are totally overwhelmed."

Two other firefighters — Assistant Chief Greg Altland and firefighter Erik Swanson — were “beaten up and bruised" but were in a stable condition and recovering in the hospital, Michaels added.

Helfrich said the community was working to help the families of the deceased firefighters. So far, no fundraising campaign have been set up for victims. However, the mayor informed everyone to keep an eye on the social media pages of the fire department for further updates.

The cause of the fire is still under investigation, although police chief Troy Bankert said preliminary reports suggested it could be arson.

People were warned to stay away from the area where the incident took place. Some of the residents living near the area, who were displaced, are being helped to find shelter by the neighborhood church.

More than 100 firefighters responded to the fire that started Wednesday, along with the York County Advanced Technical Rescue Team.

According to York City Deputy Fire Chief Chad Deardorff, the smoke alarm and sprinkler system inside the building did not go off because they were still under installation.

"It's not uncommon," he said ABC affiliate Kiii TV reported. "They weren't anywhere close to being occupied."