One of the vehicles involved in the fatal crash Saturday morning. Photo from state police.

WADDINGTON — The National Transportation Safety Board (NTSB) is set to investigate the tragic accident Saturday on SH 37 that left six people dead and more injured.

“The NTSB is launching a six-member team to conduct a safety investigation into (Saturday’s) fatal collision in Louisville, New York, involving a box truck and a medium size bus. The NTSB will be coordinating all efforts with New York State Police and other local authorities,” an announcement from the agency said.

State police confirmed six people died following crash involving a 2021 Freightliner box truck and a 2013 express bus Saturday morning.

Troopers also said one person is in critical condition with two more seriously injured. All victims were passengers traveling in the express bus.

The injured victims were transported to local hospitals, officers said.

Dozens of first responders were called to the scene as there were mass casualties. Their efforts were recognized by Mayor Mike Zagrobelny of Waddington.

“As many of you are aware, there was a terrible accident on Rt. 37 in Louisville early this morning,” he said in an online statement. “Thank you to all of the first responders from around the county including Waddington Volunteer Rescue Squad and Waddington Volunteer Fire Department who responded, thank you to St. Lawrence County dispatch for coordination of efforts, and hospital workers. Please share thanks with the responders but also grant them the grace to deal with what they may have witnessed. Thank you again for being there at the worst of times.”

The accident took place around 6:02 a.m. near Coles Creek on State Highway 37.

Troopers were assisted by St. Lawrence County Sheriff’s department, multiple fire and rescue teams; Louisville, Waddington, Norfolk, Madrid, Massena, and Seaway Valley.

The victims were reportedly transported to Massena Memorial, Canton-Potsdam Hospital, and Claxton Hepburn Medical Center.

Names of the deceased have not been released.