A horrific scene unfolded in Midland, Texas, on Thursday when a train crashed into a parade float carrying troops and their families.

Four people died and 16 others were injured in the crash. Army Sgt. Maj. Gary Stouffer, 37, and Army Sgt. Lawrence Boivin, 47, were pronounced dead at the scene.  Army Sgt. Joshua Michael, 34, and Army Sgt. Maj. William Lubbers, 43, died at the hospital.

Investigators say there were 26 people on the float, mostly military members and their spouses. 

Witnesses tell HLN affiliate KOSA that they heard the train's horn and some people were able to get off the float in time. Other troops jumped in front of their wives before the train hit.

People have reported not seeing the crossing arms come down. The NTSB says it has not confirmed that but it is investigating. Railroad officials say all the safety systems were working.

The parade was part of an event called "Hunt for Heroes," which is an all-expenses paid deer hunt for troops.

Here's how you can help the victims involved in the accident:

• Donate blood at United Blood Services Midland
• Donations accepted at Complex Community FCU