PHILADELPHIA — Federal transportation officials have shut down a bus company involved in a fatal crash on the Pennsylvania Turnpike after finding the two drivers never took required drug tests and falsified records.

The order cites Mr. Ho Charter Service of Bethlehem for drug- and alcohol-testing violations and failing to ensure its drivers comply with work-hour rules.

Authorities say the bus rear-ended a tractor trailer Monday in western Pennsylvania. They say the crash killed 39-year-old co-driver Bo Hua Tan of New York City and injured two dozen Asian tourists.

A man who answered the company phone Thursday and identified himself as Edward Ho says one bus in New York will be driven back and parked. He otherwise isn't commenting on the shut-down order.