SANFORD, Maine — Fire roared through the rear tower of the vacant five-story former textile mill on River Street, known locally as Stenton Trust, erupting just before 7 p.m. Friday night.

Flames shot out of every window in the rear of the structure.

More than 100 firefighters from 20 departments from York County and nearby New Hampshire communities fought the raging fire from the exterior of the 300,000 square foot mill.

Deputy Fire Chief Steve Cutter said firefighters were met with heavy fire as they arrived at the mill, located on the eastern border of the downtown area, and the fire quickly went to five alarms.

Sanford police just after midnight put out the word they were looking for information.

“We are seeking the public’s help with any information relating to this incident,” police said on their Facebook page. “Citizens are asked to contact our tip line at 324-3644 ext. 170.”

Cutter at a press briefing just after 10 p.m. Friday said no injuries were reported.

He called the fire “odd,” considering the time of day it erupted — it was still daylight when the fire was reported at 6:50 p.m.

He said investigators from the Bureau of Alcohol, Tobacco Firearms and Explosives, the Maine Fire Marshal’s Office, Sanford Police Department and Sanford Fire Marshal Patrick Cotter were investigating.

At the briefing, Cutter said firefighters believed the fire was contained to the rear tower, but the York County Emergency Management Agency was preparing to launch a drone that night to try to determine whether it jumped to the portion of the concrete mill that fronts on River Street.

The structure is comprised of two parallel concrete mills joined by an enclosed walkway structure.

Cutter said one wall of the rear tower was bowing and that firefighters created a collapse zone, just in case.

Firefighters used the city’s hydrant system and drew water from the nearby Number One Pond.

Folks who watched it from the intersection of North Avenue and Thompson Street said it went up quickly.

Retired firefighter Kevin Harmon was at the scene, camera in hand.

“I was here within 10 minutes of the call,” Harmon said. “I walked down High Street snapping pictures,” he said, showing images of flames roaring out of the mill’s windows.

Others watched from across Number One Pond, at William Oscar Emery Drive.

People watched everywhere and there was much speculation into what transpired — so much speculation that Sanford police on Friday night put out a message on social media, asking folks to refrain from spreading rumors.

Though empty for most of the last decade — the last known business to occupy part of the mill structure was a wooden toy company in the mid- to late 2000s — it had once been a showpiece in the Goodall textile mill empire. It later became the home of Seamloc Carpet. Later still, it housed a number of smaller businesses.

City documents list the owner as Gateway Properties LLC, a company owned by Jonathan Morse, whose address is listed as Reno, Nevada, though the mill has essentially been abandoned for nearly a decade.

The 1922 concrete mill structure was sold at auction in 2009 by a bank known at the time as Savings Bank of Maine for $210,000, though the prospective buyers never closed on the deal. They told municipal leaders at the time that the rear portion of the structure — the part that burned Friday night — was in very poor shape.

The wing of the building closest to River Street, known as Tower A, was said to have been in the best condition. The smaller “B” portion joined the two parallel mill structures. Tower “C,” the building that burned, had by 2009 deteriorated to the point that rehabilitation was considered impractical, city leaders said at the time.

The building had been stripped of electrical wiring, copper tubing associated with plumbing, and even the copper flashing from the roof had been removed, according to one of the prospective buyers back in 2009.

It had been the subject of cleanup actions by the federal Environmental Protection Agency in the late 2000s, and the city had applied for funding to assess further hazards.

City Manager Steve Buck said Friday night that officials knew there were underground storage tanks to the rear of the property, but their most recent application for federal funding was denied.

According to a 2008 EPA report, the mill was cited in 2007 for improper storage of hazardous substances, among other hazards.

The EPA in September 2008 was preparing a removal action, which it said was to include “the consolidation and segregation of all hazardous materials in and around the old mill building; decontamination and preparation of the disposal of all hazardous waste, barrels, and wall surfaces (and) excavation and disposal of contaminated soil and materials to an EPA-approved facility.”

There have been a number of smaller fires at the mill over the years, but none comparing to the magnitude of Friday night’s blaze.