LIVINGSTON, Calif. --Investigators downgraded the number of people killed in a deadly bus accident Tuesday from five to four as authorities continue working to determine what happened and more information surfaces about the bus driver.
The driver, Los Angeles resident Mario Vasquez, had multiple past violations, including driving a bus while his license was suspended.
On Tuesday, Vasquez was driving a charter bus from Mexico to Washington when he veered off Highway 99 near Livingston and crashed into a freeway sign, almost splitting the bus in half with the pole.
Four people were killed and multiple people were injured in the crash. A witness said he believes the bus driver was injured after the accident.
Another person at the scene said the driver tried to help injured passengers and ended up getting hit by a car on the highway.
National Transportation and Safety Board investigators said they will inspect the bus, highway, company, and driver.
"This initial five to seven days is a fact-finding evolution," NTSB senior investigator Don Karol said.
The sheared open bus now sits in an evidence lot after the deadly accident.
MORE: Bus company in deadly crash has history of violations, problems
Jose Bustamante described hearing problems with the bus as it passed him on the highway.
"Like clink, clink, clink, clink, clink," he said.
Bustamante said he saw the bus driver helping passengers.
"I heard him screaming, 'This is how you get out, lift up the handle, get out this way,'" he said.
But Bustamante said he later saw Vasquez on the ground. He said he believes the bus driver was hit by a passing car and was taken to the hospital.
The California DMV confirms Vasquez has a history of driving violations including illegal and improper or unsafe change of lane in Washington on Jan. 20, 2014, speeding 15 miles or more above the limit in Oregon on Oct. 23, 2014, and also a serious traffic violation in California that resulted in his license being suspended from Jan. 24, 2015 through March 24, 2015.
During that time, on Feb. 5, 2015, Vasquez was caught driving on the suspended license.
Investigators said the older model bus Vasquez drove Tuesday may not have had data recording capabilities. With or without that data, NTSB investigators will use a 3D laser to reconstruct the accident scene as part of the investigation.
Officials Wednesday released the identities of the four people who died. They're 68-year-old Jose Morales Bravo of Avalon, Calif.; 38-year-old Jaime de los Santos, 57-year-old Fernando Ramirez, and 64-year-old Petra Carillo Ruiz, who are all from Mexico.