BILOXI -- Four people are dead following a train crash with a tour bus that was stuck on the tracks Tuesday morning in Biloxi, Ms. There were a total of 42 passengers on the bus which was traveling from Austin, Texas, according to Chief John Miller of the Biloxi Police.

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Miller said it is unclear why the bus was stalled on the track.

According to Julia Clark with American Medical Response in Harrison County, Mississippi, three people were killed during the initial impact and ten were listed in critical condition.

Another ten were listed as serious with 15 said to be 'walking wounded.' The remainder of the passengers did not need medical attention, Clark said.

By Tuesday night, a fourth passenger had died from injuries sustained in the crash.

A spokesman for the bus company, ECHO Transportation, would not comment on the accident, saying only they are "mobilizing an investigation" at the moment.

The train company involved said no one on the train crew was injured.

"The eastbound mixed freight train, traveling from New Orleans to Mobile, Ala., had three locomotives and 52 cars – 27 loaded cars and 25 empty cars," said Gary Sease, CSX spokesman. "The crossing has flashing lights and crossing gates."