The Maloney family had just spent their Thanksgiving vacation in Hawaii. They were driving home from the airport in their minivan Saturday night when they had the green light on Highway 37.
California Highway Patrol investigators say 19-year-old Steven Culbertson was supposed to stop at the red light on Lakeville Highway, but instead of stopping, he clipped a Honda CRV and flew through the intersection.
"Witnesses put his speed at anywhere from 70-90 mph," Officer Jon Sloat said.
John Maloney, his wife Susan and their two children, 8-year-old Aiden and 5-year- old Grace, were all pronounced dead at the scene.
At their now empty Sonoma home, flowers lay on the doorstep.
"The whole family gone, the whole family gone, it's just terrible," neighbor Adele Ney said.
Ney had known the Maloney's for 10 years.
John was the vice president of a Novato solar company. He also has a teenage daughter who was not with them in the car Saturday night.
"It's just terrible, they were such a nice couple, I mean perfect neighbors, he was such a nice guy," Ney said.
The driver of the Honda was too distraught to talk on camera, but told ABC7 he was the first to arrive on scene. His brother, a doctor, was also with him and tried to perform CPR on Susan Maloney, but it was too late.
The crash left Culbertson brain dead. He died Sunday at Santa Rosa Memorial Hospital.
Now, investigators are left trying to piece together clues.
"Most importantly we want to find out about Mr. Culbertson; where he was going, what he was doing, what may have led him to drive recklessly," Sloat said.
The CHP says there were no immediate signs that alcohol or drugs were a factor in the crash, but they have not yet ruled that out.
