A US school bus was blocks away from its first stop today when it rear-ended a car and then ricocheted off a roadside pillar into an oncoming commuter bus.
The pre-dawn local time accident killed at least six people and injured 10, authorities said.
There were virtually no skid marks at the crash scene, suggesting that the brakes of the school bus were not forcefully applied, and leading to what Baltimore Police spokesman TJ Smith called a working theory that the driver had suffered some sort of medical emergency.
The school bus driver was killed, with at least five people on the Maryland Transit Administration bus, Smith said.
"It literally looks like a bomb exploded in the bus. It's catastrophic damage," Smith said.
The only other occupant of the school bus, an aide, was taken to a hospital, as were the car driver and eight people from the commuter bus, Smith told a news conference.
He said one survivor was in critical condition, one was in serious condition and eight had injuries that were not considered serious.
A National Transportation Safety Board team began examining the vehicles and documenting the scene, spokesman Keith Holloway said.
Baltimore Police Commissioner Kevin Davis said riders on the No. 10 MTA bus were likely going to work on a route from Dundalk, a largely blue-collar community southeast of Baltimore, toward Catonsville, a western suburb.
The school bus first hit a silver Ford Mustang, crushing its rear and forcing its nose into the pavement. Then it hit a pillar at a cemetery entrance hundreds of feet down the street.
Veering across the center line, the yellow school bus slammed into the front driver side of the MTA bus, ending about 100m from the pillar.
The school bus raked the side of the commuter bus, ending with its front end buried toward the back of the MTA vehicle on Frederick Avenue near Loudon Park Cemetery.
The wreck peeled back metal and exposed a tangle of metal and human limbs, according to a passing motorist who stopped to help, Michael Feldman.
He told WJZ-TV that the MTA driver appeared to be in very bad shape; authorities have not said if that driver survived.
The Mustang driver, Shawn Braxton, told reporters he was driving to work when the bus hit his car. He said he only remembers hearing the impact.
"Physically, I'm bruised, banged up," Braxton said. "Mentally, it's going to take a while to get myself together."
The school bus was contracted from Baltimore-based AA Affordable Transportation and served 18 students, the city's public school system said in a statement.
Federal records show the company had no violations or other crashes reported in the two years ending this past September.
One of the company's drivers, Chernell Burrows, told reporters that the late driver was kind and dependable. "I'm so sad," Burrows said.