According to officials, around 6:30 p.m., units responded to Main Street at the intersection of Marlborough Street.
At the scene, police learned a vehicle being driven by Donna Downing of Portland collided with a motorcycle being operated by Raymond Stebbins Jr., also of Portland.
Police said Downing was arrested for DUI while Stebbins was transported to a local hospital with life-threatening injuries.
The crash is under investigation.
Anyone with information is asked to contact the Portland Police Department.
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