A driver who was reported weaving over double yellow lines on Highway 116 near Petaluma seconds before a head-on collision Monday morning told authorities he fell asleep at the wheel, the CHP said.
A driver called 911 just before the Jeep Cherokee veered across Adobe Road and into an oncoming big rig.
The 6:40 a.m. collision sent the big rig into a ditch and into a power pole, toppling the pole and its live wires and creating a debris-strewn scene that blocked the road.
The major south county route remained closed for more than eight hours while PG&E crews replaced the downed pole and power lines.
Firefighters had to cut Jeep driver David Behymer, 69, of Napa, from the wreckage. He suffered major injuries.
Rig driver Anthony Michalek, 56, of Geyserville suffered moderate injuries.
Both men were taken to Santa Rosa Memorial Hospital.
Behymer was listed in critical condition Monday afternoon. CHP officials said he was expected to survive. Michalek was treated and released.
Commute traffic initially stacked up but eventually was directed around the crash via a detour to nearby Lakeville Highway.
The crash was the largest of several Monday morning in Sonoma County. While a light rain may have been a factor in some crashes, CHP Sgt. Allan Capurro said it initially didn't appear to be a factor in the Petaluma crash.
The CHP said it was looking into Behymer's reported erratic driving.
CHP officials initially said Behymer had been seen passing other drivers moments before the crash. But later, Officer Jon Sloat said Behymer only had been seen "passing over the double yellow lines."
Alcohol was ruled out as a factor, the CHP said.
Officials said cleanup of the crash site took several hours because of the PG&E work and removing the truck, which was pulling a trailer with a loader on it.
"It's a challenge getting all this stuff out of the ditch it's in," said Capurro.
A small amount of diesel fuel also spilled and was cleaned up.
You can reach Staff Writer Randi Rossmann at 521-5412 or randi.rossmann@pressdemocrat.com.
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