4 seriously hurt as bus carrying 29 flips in San Francisco on Hwy 101

SAN FRANCISCO (KTVU/AP) - Authorities say four people were seriously hurt when a charter bus carrying 29 people flipped on its side on a San Francisco freeway. 

San Francisco Fire Department Lt. Jonathan Baxter says the injuries from the crash on U.S. 101 Friday night ranged from broken bones to cuts and scrapes. 

Baxter says four had serious injuries, nine had moderate injuries and the rest had minor injuries. All adults were aboard. 

Three people remain hospitalized in fair condition while most of the injured have returned home. Some bloodied passengers crawled out roof escape hatches or broken windows. Two passengers were trapped and were rescued by firefighters.

The driver  says the bus was chartered by a group heading from San Francisco to another Bay Area city, apparently for a Christmas party. 

California Highway Patrol said the driver lost control and did not collide with another vehicle before tipping over. CHP Sgt.Vu Williams said the driver struck the center divide before flipping. 

All but one southbound lane were closed on the freeway that runs through the middle of San Francisco. 

Authorities say the driver, a 29-year-old man, is cooperating, and Baxter commended him for being the last person from the bus at the scene. The driver was given a sobriety test and was said to have passed. 

The California Highway Patrol and the San Francisco Fire Department say about 30 people were aboard the party rental bus when it crashed on U.S. 101 at about 8:30 p.m. Friday.  

St. Luke's and St. Francis hospitals in San Francisco each took two patients from the accident. San Francisco General Hospital took the remaining and majority of those who were injured. 

San Francisco Fire Department initially reported it was a double decker bus, but they corrected that information and said it was not. 

Lt. Baxter said an MCU or "hospital on wheels" was at the scene and was able to transport as many as 25 people to the hospital at once. 

A tweet was sent out at 8:21 p.m. from the San Francisco Fire Department saying the bus was on its side. 

The California Highway Patrol first reported the incident at 8:06 p.m. on southbound Highway 101 at the Cesar Chavez Street offramp.

Motorists are advised to expect delays and to use alternate routes to avoid the area. There is no estimated time to reopen the roadway.