NORTHERN CALIFORNIA – Federal, state and local agencies are continuing their efforts to understand the root causes of a deadly crash last week involving a FedEx semi, a motorcoach filled with college students on their way to a college tour and a third vehicle.

The wreck, which occurred last Thursday evening on Interstate 5 near Orland, killed 10 people and injured 34 more.

Among the dead are the semi and bus drivers, several students and chaperones, and a Humboldt State University employee, officials reported.

A southbound FedEx-owned 2007 Volvo semi towing two trailers crossed the freeway median – which is lined with oleander bushes, not concrete barriers – and hit a 2013 Nissan Altima driven by Bonnie Duran, 53, of Lake Tapps, Wash., before hitting the 2014 Setra motorcoach head-on, according to the reports from the California Highway Patrol and the National Transportation Safety Board.

The motorcoach, owned and operated by Silverado Stages of San Luis Obispo and in service barely a month, was carrying 43 students from dozens of Los Angeles-area high schools and three chaperones to a campus tour event at Humboldt State University, officials reported.

NTSB member Mark Rosekind reported Saturday that, based on tire marks at the scene, investigators concluded that the FedEx truck did not brake as it was crossing the median into the path of the bus.

He said that Duran told investigators that she saw flames come from underneath the FedEx truck's cab as it was coming across the median.

Glenn County Sheriff Larry Jones reported that his agency was working with a medical examiner to identify the victims.

Jones said four autopsies were completed on Friday and efforts were being made to complete the remaining five autopsies over the weekend.

He said dental records are being provided to a forensic odontologist to commence the process of identification. Should there be no dental records available for a particular victim, they will use DNA identification, will he said will lengthen the time factor.

“A request has been made through the Governor’s Office of Emergency Services to expedite this process, should the need arise,” Jones said.

Jones said he does not anticipate having an update on the victims' identities until midweek.

So far, the only victim's name to be formally released is that of Arthur Arzola, a Humboldt State Admissions Office staffer. The university said Arzola was accompanying the students on their trip.

On Saturday evening, about 24 hours after the team of NTSB investigators arrived on scene from Washington, DC, Rosekind gave an update on new developments in the case to reporters at a briefing in Red Bluff and posted online.

He said that on Friday night the parties to the investigation were identified, including the CHP, the California Department of Transportation, the Federal Motor Carrier Safety Administration, FedEx and Silverado Stages Inc.

On Saturday, NTSB investigators were at the crash scene, where they studied tire marks and the freeway median, and examined the badly burned vehicles, Rosekind said.

Investigators measured the freeway median, which is 58 feet from edge to edge. Rosekind said that in cases where medians are over 50 feet wide, barriers are an option, not a requirement, for Caltrans.

The tire marks indicated that the FedEx semi left the road at a 10-degree angle from its southbound lane and went into the median, Rosekind explained.

He said the tire marks indicated the FedEx truck didn't brake while traveling through the median or into the northbound lanes.

The motorcoach's path showed 145 feet of tire marks that indicated evasive maneuvers, Rosekind said, including that the bus was steered to the right – away from the semi.

NTSB investigators are organizing information from FedEx, plan to visit the Los Angeles terminal from which the motorcoach departed and will meet with personnel from the Los Angeles Unified School District to discuss how travel arrangements, Rosekind said.

He said they also will interview survivors, which will be especially critical in understanding how they were able to escape from the burning bus.

CHP has arranged for the NTSB to get blood samples from both the bus and semi drivers, which Rosekind said will be sent to the Civil Aerospace Medical Institute in Oklahoma City.

The samples will be tested for drugs and alcohol, with tests of hemoglobin also to be done to try to discern if the drivers had inhaled smoke at the time of the crash, Rosekind said, an important consideration now that it has been reported that the FedEx truck may have been on fire.

Rosekind said that there were two motorcoach drivers. The original driver drove the bus from Los Angeles to Sacramento, where due to hours of service the vehicle's driving was taken over by the second driver, who was killed in the wreck.

He said investigators are examining how people got out of the bus, and obtaining dispatch logs from first responders as well as autopsy results.

He said some individuals who were killed had been ejected from the bus. Seat belts are among the factors investigators are examining, with Rosekind noting that the bus was equipped with lap and shoulder belts.

He said NTSB is looking at whether or not seat belts would have prevented those individuals from being ejected.

Investigators already have conducted an initial inspection of the vehicles' mechanical conditions. “It's extremely difficult due to the fire damage,” Rosekind said.

However, Rosekind said that the motorcoach's electronic control module survived the crash and appears to be available for download, with the NTSB to send that information to one of its labs for analysis.

It's not yet clear what information was actually recorded, said Rosekind, who noted that at the time of purchase, the motorcoach's operator was able to choose how much information the device will record.

He said the electronic control module for the FedEx truck was destroyed. However, NTSB investigators plan to remove the truck's transmission, and should be able to tell the gear the semi was in at the time of the crash in order to get a speed range.

They also will remove the steering box, which will help determine how far the steering wheel had been moved and in what direction, Rosekind said.

Rosekind said Duran's Altima had come from behind the motorcoach, passed on its left side and was in front of it when the FedEx truck came across the median and hit the Altima behind the driver before hitting the bus.

The NTSB continues to seek additional witnesses to the wreck, Rosekind said.

He asked anyone who saw the crash to contact law enforcement agencies or the NTSB directly at This email address is being protected from spambots. You need JavaScript enabled to view it. .

“We will not determine a probable cause while we're on scene,” said Rosekind. “We're not going to speculate. We're not going to analyze.”

He acknowledged that, “The big question is why,” but said the investigation is still in too early of a stage to make that conclusion.

Email Elizabeth Larson at This email address is being protected from spambots. You need JavaScript enabled to view it. . Follow her on Twitter, @ERLarson, or Lake County News, @LakeCoNews.