STETSON – A motorist was killed Monday afternoon when the convertible she was driving left Route 143, knocked down a utility pole and rolled over, partially ejecting the driver.

The woman, whose identity was not being released until family members had been notified, wasn’t wearing a seat belt, State Trooper Forest Simpson said Monday.

A nurse who was driving by shortly after the accident occurred found that the driver still had vital signs, “but rescue was not able to revive the person,” Simpson said.

The accident occurred about 1:30 p.m., a half-mile from the intersection of Route 143 and the East Newport and Mt. Pleasant roads as the driver was heading south toward Etna from Stetson.

Another motorist came across the accident shortly after it happened and saw the utility pole fall onto electric wires and told investigators the wheels of the convertible were still spinning.

A state police dog searched the vicinity of the accident to determine whether anyone else had been in the car and thrown from it, but Simpson said no one was found.

Investigators also didn’t find any skid marks leading up to the crash. A state police accident reconstructionist will assist investigators in trying to figure out what caused the crash.

The car was to be towed to a garage in Hampden where it will be examined to determine whether a mechanical problem existed, while blood samples from the deceased driver were taken to assess whether a medical condition might explain what happened, Simpson said.

Investigators may also be considering what role speed played in the fatal accident. Authorities were told that a car similar to the one that crashed was seen speeding in the area earlier, Simpson said.

“There’s nothing being ruled out at this point,” he said.

Although some things remain unclear, Simpson is convinced that had the motorist been wearing a seat belt, the outcome would have been different.

“If anything could have made this a lot better it would have been a seat belt,” Simpson said.

Workers from Central Maine Power disconnected power to the section of damaged utility lines Monday afternoon.