The National Transportation Safety Board (NTSB) held a press conference Monday afternoon to outline the agency's approach to the investigation into the quadruple fatal bus crash involving a softball team from North Central Texas College on Friday.
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NTSB spokesperson Robert Sumwalt said the investigation includes efforts from several groups of experts from diverse fields of study.
As of Monday, investigators attained and delivered subpoenas for the medical records of the truck driver, who reportedly crashed into the bus traveling at 70 mph on Friday after crossing the median.
NTSB has also contacted the truck driver's attorney with a request for an interview, according to Sumwalt.
Sumwalt said the agency is compiling maintenance records for both the truck and the school bus, collecting roadway design plans for the area near the crash site and looking at the criteria for when median barriers should be installed.
Sumwalt said the NTSB is also working to obtain the 911 calls from that night, among other things.