Tanker truck leak at Kaiser building in Santa Rosa contained

A tanker truck that was leaking liquid oxygen at the Kaiser Permanente North Medical campus in Santa Rosa has been contained.

Firefighters responded to a small explosion and fire involving a Matheson tanker truck in the parking lot of the campus at around 2:30 p.m. Wednesday.

The tanker was carrying cryogenic oxygen, according to Santa Rosa Assistant Fire Marshall Paul Lowenthal. Firefighters quickly extinguished the fire but took nearly two hours to contain the leak.

The truck's driver was hospitalized with unknown injuries, the Press Democrat reported. No patients or medical employees were injured.

"It sounded like the start of an earthquake," Kaiser employee Jenna Ausiello told the newspaper. "That's what I thought was happening. The windows shook ... it was just a big boom."

Matheson is an industrial and medical gas supplier, fire officials said.

Initial emergency dispatch reports indicated that the truck had crashed into a building at the medical complex. Authorities said later that there was no crash and the incident is considered an industrial accident.

Assistant Fire Marshal Paul Lowenthal said something apparently went wrong with the connection as the truck's tank was delivering oxygen to an on-site tank at the offices.

Most of the truck seemed undamaged. But the back of it appeared to be burned black and some metal parts near the back appeared to be twisted.

The entire Kaiser North campus on Old Redwood Highway was evacuated but there was no impact to Kaiser Hospital on Bicentennial Way. Buses and ambulances were sent to evacuate employees and patients, some of whom were in wheelchairs and on stretchers.

CHP closed both directions of Highway 101 between Bicentennial Way and River Road but re-opened the highway at around 4:40 p.m. Old Redwood Highway was closed between Cardinal Newman High School and Mendocino Avenue. All roads were expected to re-open by 5:40 p.m. CHP tweeted in an update.

Kaiser is expected to re-open the evacuated buildings on Thursday as usual.

Associated Press contributed to this report