The driver survived with only minor injuries, officials say.
Officials say two adult females were killed and that one man with major injuries was transported to the hospital. Three adults with minor injuries were also transported along with a child, who was taken to the hospital as a precaution.
The bus crashed while traveling in the northbound HOV lane, according to the CHP. San Jose Fire Capt. Christopher Salcido said 20 people were aboard the bus when it crashed.
PHOTOS: Greyhound bus overturns on Hwy 101 in San Jose
There is no word on what caused the bus to crash. Officials say the bus appears to have been the only vehicle involved.
The CHP said the bus was traveling in the northbound HOV lane when it overturned.
The bus is blocking both the northbound and southbound HOV lanes of Highway 101. The CHP estimates it will take until at least 4 p.m. Tuesday to clear all lanes.
Driving up to Greyhound bus crash on NB 101 to 85. 2 dead and 18 injured. pic.twitter.com/zSap17uGVY— Matt Keller (@MattKellerABC7) January 19, 2016
Fatal bus acc SSJ. On it's side. Backed yo to E Dunne. 1 hour and 10 mins to drive what usually takes 8 mins pic.twitter.com/eVoXK8tDVB— SueHallTraffic (@SueHallTraffic) January 19, 2016