The crash was reported at about 11:20 a.m. on northbound Highway 880 near the Davis Street off-ramp.
A vehicle overturned in the crash, causing major injuries to someone inside, CHP Officer Kevin Bartlett said. He did not know the extent of that person's injuries.
The crash blocked the three right lanes of the highway until shortly after 12:30 p.m., when all lanes reopened, Bartlett said.
