Investigators believe a woman northbound on 287 Monday afternoon entered the ditch twice and slammed into a tree because of possible medical conditions.

It happened at around 2:30, just south of Bellevue, and both lanes of US 287 were shut down for about 15 minutes for Air Evac.

DPS Sergeant Dan Buesing says a 71-year-old Amarillo woman was flown to United Regional with serious injuries.

He says two others in the car were not injured, and all were wearing their seat belt.