ROCKPORT – A moose wandering across U.S. Route 1 early Tuesday caused a chain of events that left part of the highway closed for most of the day.

A truck driver, heading north from Rockland, swerved the 18-wheeler he was driving to avoid the moose just north of South Street, he told police, and the rig rolled off the road.

Concern about the chemicals in the truck, which could have caused a fire or explosion, led to law enforcement officials detouring traffic around the accident.

Craig Cooley, administrative assistant with the Rockport Police Department, said the accident was reported at 3:25 a.m. In his report, Sgt. Paul Pinkham noted that the driver, Anthony Archambault, 36, of Jefferson swerved and his vehicle struck a guardrail on the right, then left the road, rolling the truck onto its side.

Cooley said Archambault escaped serious injury, but he was unsure whether the driver was transported to the hospital.

The 1998 Mack, registered to Composites One of Rockland, sustained about $200,000 in damage, he said.

About three minutes after the truck rolled, another 18-wheeler, also heading north on Route 1, became entangled in utility wires that were dangling low from the first crash, Cooley said.

That truck, a 1981 Mack driven by Loy Linscott, 42, of Rockland, had about $8,000 in damage, he said. Linscott was able to get out of the vehicle without coming into contact with electric lines, Cooley said.

The 1981 Mack was registered to F.J. O’Hara and Son of Rockland, he said.

The Composites One truck was carrying several chemicals, which prompted a response from a Rockland-based hazardous material team and from the state Department of Environmental Protection.

Donald Robishaw, assistant fire chief with the Rockland Fire Department, said the truck was carrying chemicals associated with Fiberglas boat-building, including acetone; n, n-dimethylaniline; ethyl alcohol; and methyl-ethyl ketone peroxide.

The chemicals, if they came together on spilling, posed a threat, he said.

“Essentially, if they mix, they become unstable and can cause a fire or an explosion,” Robishaw said. The mixture also could give off a toxic gas, he said.

Robishaw was unable to say whether the chemicals spilled.

Another Composites One truck was brought to the scene about midday Tuesday, and the damaged truck was unloaded. In the early afternoon, the materials were moved back to Rockland, where Composites One has a plant in the city’s industrial park.

A man answering the telephone at the business refused to talk to a reporter.

Route 1 was reopened to traffic about 4 p.m. Tuesday.