The Mission Boulevard onramp to Interstate Highway 680 in Fremont was closed Thursday night because an overturned big-rig left 23 tons of rocks and 20 gallons of diesel fuel spilled on the roadway, according to the California Highway Patrol.
The big-rig overturned shortly after 5 p.m. It had rolled over leaving boulders on the roadway, the CHP said.
Cal Trans was called to help remove the 23 tons of rock on the roadway and the CHP issued a Sig-alert that the onramp was closed at 5:42 p.m.
A hazardous materials team was called at about 8 p.m. to help clean up the diesel fuel spilled on the roadway, the CHP said.