Investigation Underway in Fiery Tennessee Train Crash

About 5,000 residents evacuated after the derailment of a freight train carrying flammable and toxic gas in eastern Tennessee were allowed home on Friday as investigators looked into the cause of the fiery accident. Authorities were examining the black box from the CSX Corp train that derailed with one tank car bursting into flames at midnight Wednesday in Blount County, near Maryville, Tennessee.