FITCHBURG, Mass. — An 8-year-old Massachusetts boy is being credited with helping saving his father after their car crashed through a guardrail and landed upside down on a sandbar in the middle of a river.

Authorities say Eugenio Garcia of Fitchburg was trapped in the vehicle in the Nashua River after the crash, which occurred at about 3 a.m. Thursday.

But his son, 8-year-old Joshua, wriggled out the wreckage, waded through the rushing water, scaled an embankment, then walked more than half a mile home to alert his mother, who called 911.

Garcia was rescued at about 3:30 a.m., then treated for minor injuries and released from a hospital.

Fire officials say if the car had landed in the water, both father and son likely would have died.

The crash remains under investigation.