Sonoma County authorities are investigating three separate weekend traffic accidents that left four people dead over a single afternoon and evening.
The Press Democrat reports the first tragedy occurred Saturday afternoon on Highway 1 near Salt Point State Park when a vehicle carrying tourists from Germany flipped over an embankment, killing a male passenger.
Just over two hours later, an elderly couple died after their Mercedes veered off Highway 101 in Santa Rosa and slammed into a tree.
Later that evening, a 52-year-old Santa Rosa motorcyclist was killed on Porter Creek Road after passing cars on the wrong side of the road and rear-ending a stopped pickup truck.
The California Highway Patrol says the exact causes of the first two collisions remain under investigation.