The California Highway Patrol said Robben's 2007 Ford F-250 work truck pulled out of a driveway of the cemetery, stopped at the fog line on Midway Road, then drove into the path of the oncoming 2008 Peterbilt tractor-trailer around 8 a.m.
The big-rig struck the truck broadside. The truck overturned partially ejecting Robben who died at the scene.
Eight members of the Dixon Fire Department and the California Highway Patrol responded to the crash. A chaplain and a critical incident stress counselor were available at the fire station that day. Firefighter Josh Smotherman said.
Smotherman said members of the fire department knew Cody Robben since he was a child because Robben's father Tony Robben retired as captain after 30 years with the fire department.
"He's been with us since birth. I've known him for 15 years," Smotherman said.
Cody Robben joined the fire department as a volunteer in 2006. He was working for his employer checking agricultural fields for pests at the time of the accident, Smotherman said.
"He was an awesome guy. You can't find a person to speak ill of him. He was active in fundraising and everything we did and he helped the guys under him," Smotherman said.
Robben loved the outdoors and wanted to follow in his father's footsteps, Smotherman said.
The Dixon Fire Department responds more often to vegetation fires than structure fires, and Robben "embraced the wildlife aspect" of the job, Smotherman said.
Days before his death, Robben was off duty on July 20 when he came upon a 13-year-old boy who was unconscious on Meridian Road in a rural area.
The teen was with friends and he fell and struck his head, Smotherman said. His friends could not revive him.
Robben called the fire department and the boy was flown to the UC Davis Medical Center in Sacramento and survived, Smotherman said.
"Without Cody's intervention, the results could have been tragic. This was Cody's nature; to pitch in when it was needed, anytime, anywhere," the fire department said on its website.
A private family viewing will be held between 4 and 5 p.m. Wednesday at the Milton Carpenter Funeral Home, 569 N 1st St., Dixon. A public viewing will follow between 5 and 8 p.m.
A funeral service is scheduled for 10 a.m. Thursday at the Dixon Community Church, 955 East A St. Burial is at the Silveyville Cemetery, 800 S. First St. in Dixon. A reception will follow at the Dixon May Fair grounds.