The tire popped with a tremendous bang, lifting Edward Zygmant from his sleep around 4 a.m. His two dogs were barking and he pulled himself from his bed.

The noise had come from Interstate 95, he thought, just a couple hundred yards from his house on Kings Drive.

He turned on his fire dispatch radio to find out what was going on. His guess was right: An accident had occurred on the stretch of highway right behind his house.

The Fairfield County Hazardous Materials Unit was being called in.

Normally, Zygmant wouldn't go to work for another three hours. But as Westport's fire marshal, a member of Fairfield County's Hazardous Materials team and a resident of the closest street in town to the unfolding potential disaster behind his house, his Monday morning was starting early.

He climbed into his car where he had extra gear stored, and drove the roughly quarter-mile stretch up the Post Road to the Exit 19 on-ramp.

He estimates he was on scene within five or 10 minutes of climbing out of bed.

By the time he arrived, firefighters with Southport's Engine 4 were already fighting flames that reached up and around the trailer, which had been disconnected from the front of the truck.

Inside the trailer were 8,600 gallons of Methanol, a flammable, toxic liquid also known as "wood alcohol."

The firefighters' hose was hooked up to their engine, a finite supply. Another crew had just tapped another hose into a nearby fire hydrant. They were dragging it toward the flames.

When the back wheels caught fire on the tanker truck heading north on I-95 Monday morning, a range of outcomes were possible.

"It was a very close call," said Joe Palmieri, president of Connecticut Tank Removal of Bridgeport, which was called in to remove the methanol from the trailer when the fire was finished. "If the fire department had lost the tank, if the product had ignited, it would have been an environmental catastrophe and a very large fire."

According to Zygmant, the tank was double-walled with an insolation jacket in between. The fire breached the outer wall and was working on the insolation.

Assistant Fire Chief Scott Bisson said that the Fairfield firefighters arrived and began an immediate fire attack to quell the flames and protect the exposed tank from a so-called BLEVE, "a boiling liquid expanding vapor explosion."

Meanwhile, emergency response teams used Reverse 911 to phone the houses along Kings Drive and Kings Lane and evacuate the area. If the trailer ignited, gas fumes would shoot into the air. As Zygmant was arriving on scene to help prevent that, police officers were going door-to-door on his street to expedite the evacuation.

All told, the Fairfield Fire Department sent Engines 1, 2, 3, 4 and 5, Rescue 1, Ladder 2, and Cars 1, 2, 3, and 5. Westport sent an engine to cover Fairfield headquarters, Zygmant said. Bridgeport sent a unit to cover Jennings Road.

And before the job was finished, Zygmant was called away to a structure fire in Westport.

All in a Monday morning's work.