ROCKINGHAM, N.C. -- Federal investigators are now looking into the bus crash that killed four and injured 42 over the weekend.
The charter bus was taking the Ramah Juco Academy football team to its inaugural game Saturday afternoon when the bus blew a tire. The bus hit a guardrail and an overpass.
National Transportation Safety Board investigators inspected the bus, paying close attention to the tires.
An NTSB spokesperson says investigators will examine the tread wear, the tire pressure and the age of the tires.
Last year, a special federal investigation found the tire registration and recall information is largely ineffective. NTSB also found the tire and automotive industries are not sufficiently warning drivers about the risk of aging tires.
Investigators have not yet determined what caused the tire to blow in this crash.
A Highway Patrol spokesperson says the bus was built in 1993 and is registered to Sandy River Baptist Church.
As a private bus, it is not subject to federal inspections.
Records show that the bus is not allowed to be used as a "for-hire operation."
Investigators are still examining whether the team officially chartered the bus for the trip.
Spokespersons for both highway patrol and NTSB say their investigations could take weeks or months.
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