A Santa Rosa man heading for church with his wife early Sunday ran over a woman lying on the ground in a Santa Rosa Avenue crosswalk, the CHP reported.
Driver Irvin Sandoval, 24, who works for a local ambulance company, called 911 and began giving the woman medical aid, according to the CHP.
Melissa Tucker, 29, was rushed to Santa Rosa Memorial Hospital with severe injuries and later flown to Stanford Medical Center.
Why the woman was on the roadway prior to being struck remained unclear, said CHP Officer Bob Powers, who was investigating the crash.
Tucker may have been hit and knocked to the ground by a car whose driver didn't stop or she could have collapsed prior to Sandoval hitting her, he said.
The crash was at Santa Rosa and East Robles avenues, just shy of the city limits as the avenue turns to a more rural landscape.
Tucker had been living in the area temporarily, said Powers.
With the daylight savings time change Sunday morning, it wasn't completely light at 7:10 a.m. as Sandoval headed south in his Honda Accord.
CHP Officer Nenad Gorenec said the driver told officers, "It looked like a garbage bag in the lane. When he realized it's not, it was too late and he ran over the woman."
The driver immediately stopped.