Local police and fire officials, along with the State Fire Marshal, are investigating the source of a fire that took place Saturday around 9 p.m. at the Department of Public Works (DPW) on Sandy Lane.

Captain Robert Nelson of the Warwick Police Department (WPD) said that while the suspected cause of the fire is unknown at this time, it is thought to be electrical.

“Detectives have not made a determination as to whether there was foul play involved,” Nelson wrote in an e-mail to the Warwick Beacon yesterday. “We continue to work with the WFD [Warwick Fire Department] and DPW to determine the cause of the fire.”

The fire severely damaged three automated sanitation trucks, which were last used Saturday afternoon and returned empty to the city yard around 2 p.m. The cabs of the trucks endured the brunt of the trauma, and nearby vehicles were also impacted, as their windshields and grills melted. The trucks are kept in the city yard, which is locked. The fire is thought to have started in one truck and spread to those on either side of it.

At least $1 million worth of damage was incurred. The trio of trucks each cost approximately $250,000 to replace, along with repairs that need to be made to surrounding vehicles. No one was harmed during the blaze or cleanup.

Nearby residents reported hearing three explosions that sounded like fireworks or gunfire. In a statement to the Beacon on Sunday, Mayor Scott Avedisian said while the investigation is on-going, it is unlikely that the shooting range adjacent to the DPW had anything to do with the situation.

“In addition to the investigation by the State Fire Marshal, our Police Department will be reviewing footage from the security cameras that are at the Public Works yard and garage,” Avedisian wrote.

Representatives from the Rhode Island Interlocal Risk Management Trust, the city’s insurance company, were on scene to evaluate the damage and verify if the trucks can be salvaged.

The noise was heard by people at Warwick Veterans High School, as the annual basketball game between the WPD and WFD commenced during the time of the explosions. Some residents as far away as Hoxsie and Conimicut said they heard booms that shook their homes.

“I was in my backyard and I heard three loud explosions,” said Hoxsie resident Heather Morton, adding that she finds the incident suspicious and odd. “I then heard several sirens for 20 minutes. I [took] a ride there a little while after. [I didn’t see] flames, but I saw smoke and tons of police, fire and rescue vehicles.”

Other local residents, including Tammy McMahon and her family, also heard three distinct explosions. She lives on Hilton Road, which is parallel to Buckeye Brook.

“We heard one big boom and our daughter came running out of bed scared,” she said. “We were all confused as to what we heard. Then we heard it two more times. The noise sounded like it was next door. We heard fire trucks and knew something was wrong. My neighbor was saying she was outside and could see smoke.”

Nelson wrote that he doesn’t have information about any explosions that may have occurred other than those normally associated with a vehicle fire containing combustible elements.

Battalion Chief Peter Sisson reported that the fire was fueled by diesel inside the trucks, which each store approximately 100 gallons of fuel in aluminum tanks. He also said that two tanks, as well as hydraulic lines on the trucks, were melted. One truck still had garbage in it.

Garbage and recycling pickup will continue as scheduled, with sanitation workers temporarily using older trucks.