The huge, six-alarm fire that burned down an Alexandria warehouse on Sept. 2 was no accident.

WASHINGTON – The huge, six-alarm fire that burned down an Alexandria warehouse on Sept. 2 was no accident.

Fire marshals with the Alexandria Fire Department, working with the Bureau of Alcohol, Tobacco, Firearms and Explosives have ruled out all accidental causes and determined the fire was incendiary in nature.

“It’s not the same thing as arson. Arson has a specific legal definition,” Alexandria Fire Chief Adam Thiel told reporters during a briefing Tuesday night in Alexandria’s Market Square.

Investigators have also identified a person of interest in connection with the fire, and the case has been forwarded to prosecutors.

“Ultimately how this case will be prosecuted and what will happen next is up to the Commonwealth’s Attorney,” said Thiel.

The chief said investigators have been working day and night for a week inside the 43,000 square foot warehouse.

“There’s a great deal of evidence. This was an exhaustive investigation.”

Officials estimate the damages and loss from the fire to be about $6 million.

The fire broke out around midday on Labor Day at the three-story building along South Pickett Street and it took firefighters four hours to contain.

Dark smoke could be seen for miles.

A water main break on the same day and the same block as the fire complicated the response.

“This would have been a major fire regardless of the water main break, because of the nature of the fuels involved, the nature of the building and because of the day,” Thiel said.

Three Fairfax County firefighters and one Alexandria firefighter were taken to area hospitals with minor injuries while battling the fire.

The warehouse housed a construction and recycling company.

Asked if there are any worries about the person of interest setting another fire, the chief answered this way: “We’re not concerned at this point about the person of interest doing anything else.”

A man told the Washington Times he saw a drone flying over the warehouse as it burned, and he took photos of it.

“We don’t know anything else about the drone that was allegedly seen flying over the fire,” Thiel said when asked about it.

Below is video of the Sept. 2 fire courtesy WTOP’s Hillary Howard:

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