Massive flames drew a massive response to a rare seven-alarm fire inside what is likely a vacant West Baltimore warehouse, where crews continued to work to extinguish the blaze more than 24 hours after it started. 

The federal Bureau of Alcohol, Tobacco, and Firearms (ATF) is leading the investigation.

"In big fires like this, they bring in the ATF right away, and I think the ATF, they are the best trained, the best fire investigators we have," said Dr. Peter Sunderland, with the University of Maryland A. James Clark School of Engineering, who specializes in fire dynamics.

The warehouse near North Bentalou Street and Edmondson Avenue was filled with old mattresses. 

"These mattresses, they're full of foam and stuff that burns with really black smoke," Dr. Sunderland said. "The black smoke that gets in your lungs, it's very toxic. I'm glad they evacuated some of those buildings."

Smoke still billowed through the gray, rainy skies above the massive brick structure Tuesday afternoon. 

"My lungs, my lungs! I should have on a mask now," said Vinette McPherson, who lives a block away from the fire. "When I go upstairs and look out, I see the fire. It was very, very sad."

Challenging location

Drone video showed flames remaining in the middle of the structure Tuesday morning.

The building's location is challenging. 

On one side, it is against railroad tracks—the vital travel link for the Northeast corridor. Tightly packed row homes line the other. 

"To me, what makes it hard is the proximity to Amtrak and MARC. That's difficult. And it's in a residential neighborhood," Dr. Sunderland said. 

Century-old structure 

Built in 1925 by the Ward Baking Company over the protests of neighbors at the time, the building extends several stories underground, with a basement and a sub-basement. 

The non-profit Baltimore Heritage said the warehouse was designed by C.B. Comstock, a New York-based refrigeration architect and engineer.

Past citations

WJZ Investigates found 10 citations from the city's housing department between 2016 and 2022 for trash in and around the property, high grass and weeds, and bulk trash.

"We think maybe part of it was vacant, maybe part of it was being used. We know there were supplies," said Baltimore Fire Chief James Wallace. "There were things stored up in there. We don't know if the building was totally vacated yet. That's part of what the ATF brings is they bring that ability to really look historically at this whole building."

Water pressure 

The fire strained the water grid, with 6-inch mains in the area not built to handle the demands of a fire this size. 

"95% of the fires we fight, that's perfectly adequate," Chief Wallace said. "We get into a building that is this size, we're not only trying to suppress the fire, we're trying to protect all the exposures around it."

Past fires 

While a seven-alarm blaze is not common, Baltimore is no stranger to massive fires.

December's wind-driven Camp Small fire tore through the wood recycling yard and shut down the JFX.

Nine months earlier, a fire at a scrap metal facility near the stadiums spread to a vacant warehouse.    

In 2019, at a blaze at a vacant warehouse just three blocks from Monday's fire, the acrid smoke from tires inside could be seen for miles.

Long cleanup

The clean-up from the seven-alarm mattress warehouse fire will not be fast or easy.

"There's no point in getting the firefighters in harm's way if they really expect nobody's inside that building, and I think it's part of the strategy to just let it burn out. Let it burn itself out, but it could take days," Dr. Sunderland said. 

The chief said representatives of the building's owner have been helpful. "They've absolutely been cooperative. I don't know about whether or not the building was open,  breached, locked, I don't know yet," Chief Wallace said. 

Tuesday evening, a yellow condemnation notice was posted on the Edmondson Avenue side of the structure, noting plans for demolition.