Alameda County Fire fighters responded to a report of wires down at about 3:30 a.m. in front of the Camp Wilmont Sweeney juvenile hall at 2600 Fairmont Drive, Battalion Chief John Walsh said.
When firefighters arrived, they found a tractor-trailer on fire, surrounded by live wires, Walsh said. The big-rig brought down the wires, he said.
Two men, transporting laundry from Solano County to the juvenile hall, evaded the "high possibility" of being electrocuted by jumping out of the truck to safety, Walsh said.
PG&E crews arrived at the scene at about 4:30 a.m. and deactivated the wires, allowing firefighters to put out the fire, which they did shortly after, the battalion chief said.
Alameda County sheriff's deputies evacuated about 35 low-risk juvenile offenders from Camp Wilmont Sweeney when the truck was ablaze, Walsh said.
No injuries were reported.