Officials suspect arson caused the fire that tore through a Chelsea warehouse last month, requiring two dozen fire departments to combat, and are asking for the public’s help in catching those responsible.

“The exact cause of the fire remains under investigation, but the evidence so far suggests that one or more people were present when the fire broke out,” Jon Davine, the Massachusetts Fire Marshal, said. “We’re extremely fortunate that no one was hurt — or worse — by the fire or structural collapse.”

Flames first spread through the abandoned warehouse at 1 Forbes St. in Chelsea at about half-pasty midnight on Nov. 18. The severity of the fire quickly escalated, with the first eight of nine alarms struck within 20 minutes.

Eventually, 24 other fire departments would join Chelsea FD in combatting the blaze. The surrounding area was shut down from normal operations, including the shuttering of schools and MBTA services, as firefighters tackled remaining hotspots and investigators did their work.

“I want to thank our Chelsea firefighters and mutual aid partners for their remarkable work protecting the community from this massive fire,” said Chelsea Fire Chief John Quatieri. “I also want to recognize the proactive work that helped us achieve this result with limited access to water. Weekly inspections at the site and aggressive pre-planning for a fire of this nature were instrumental in containing it.”

The warehouse hasn’t had electricity for “years,” according to Davine’s office. It has become a spot for gatherings of teenagers and for homeless people.

Officials ask that anyone with any information on the cause of the fire to call the Arson Watch Reward Program’s hotline at 1-800-682-9229. The program is coordinated by the Massachusetts Property Insurance Underwriting Association and offers rewards of up to $5,000 for information that detects or prevents arson crimes, according to the state fire marshal’s office.

The address is home to four separate buildings, according to the Chelsea assessor’s office, with the largest by far being a huge warehouse of 113,394 square feet. The entire property with all four buildings was sold for $11.55 million in 2014 and is registered to a California limited liability corporation. The property was last assessed this year at $21,486,900, which includes nearly $5 million in improvements over its purchased state.

The city estimated a more than $8.5 million replacement cost for the 1900-built large warehouse alone.

The fire departments that helped Chelsea FD were Revere, Everett, Boston, Medford, Somerville, Winthrop, Lynn, Malden, Saugus, Melrose, Cambridge, Wakefield, Brookline, Belmont, Stoneham, Waltham, Woburn, Newton, Reading, Arlington, Lexington, Massport, Watertown, and Quincy.