>>> there's been a terrible accident involving a church bus on tennessee 's i-41. the bus filled with seniors crashed into a semi and an suv. at least eight are dead tonight. more than a dozen injured. we have a late report from nbc's tom costello.

>> reporter: on i-40 near the i-81 split in northeastern tennessee , smoke, fire, and miles of backup. state troopers say a church bus blew a tire and crossed the median, slamming into a tractor-trailer and sport utility vehicle.

>> it was a loud boom. it sounded like an explosion. i was several miles away .

>> reporter: at least eight people are known dead including six senior citizens on the church bus that had come from a jubilee gathering returning home to statesville, north carolina . people along i-40 say they have seen a lot of crashes lately.

>> in the last six months there's been quite a number of 18-wheeler accidents in this area.

>> reporter: after a series of horrific bus crashes in recent years involving dozens of fatalities is department of transportation began cracking down on bus operators.

>> come off the bus. we have to do an inspection.

>> reporter: the focus, the busy i-95 corridor from washington to florida. roughly 40 discount bus companies were put out of business. it is not the clear if the bus was hired or houn owned by the church.

>> while churches operate buses they don't have professional drivers and often don't operate to the same standards professional bus companies do.

>> reporter: in northeastern tennessee with so many dead i-40 is ex-ebb expected to re main shut down into the night . tom costello, nbc news, washington.