SACO — State police say a Massachusetts woman and her five-year-old son are lucky to be alive after their sports utility rolled over three times before bouncing off a guardrail and landing upside down in the southbound passing lane of the Maine Turnpike.

State Police Trooper David Alexander said the crash, which took place in Saco around 2 p.m. Sunday, caused traffic to back up for about five miles.

The driver of the 2002 Chevrolet Blazer, 26-year-old Jaimie Overlock of Taunton, Mass., was transported to Maine Medical Center with non life threatening injuries.

Her son, who was riding in a booster seat, was also taken to the hospital to be checked out. No one else was in the vehicle.

A registered nurse and the town of Wells’ fire chief happened to be following Overlock when the crash occurred and tended to her injuries while emergency crews made their way to the crash site, Alexander said.

“There were some good samaritans today,”  Alexander said.

The cause of the crash remains under investigation. Alexander said she lost control of her vehicle.