BILOXI, Misssissippi -- The National Transportation Safety Board (NTSB) on Tuesday released a report concerning the March 7, 2017, crash between a tour bus and a train in Biloxi, Mississippi, that killed four people from a Bastrop, Texas, church.

The report found the freight train company and the city of Biloxi “failed to mitigate known safety hazards at a Biloxi, Mississippi, grade crossing."

A chartered ECHO Transportation bus was carrying 49 senior citizens to a casino. The bus grounded on a “high profile” crossing. As the bus driver attempted to free the vehicle from the tracks, a CSX freight train approached.

The train struck the bus at 19 mph. In addition to the four people killed, 37 passengers were injured. No one on the train was injured.

The grade crossing dates back to 1870 and was reconstructed in 1977. It had an unusually high vertical profile, the NTSB wrote.

In the three years prior to the crash, there were 23 known vehicle groundings there.

The final report will be available in several weeks.