The State Fire Marshal is investigating a fireworks malfunction that injured three people at Sunday River Ski Resort on Barker Mountain Road in Newry on Saturday.

Maine State Police say a 5-inch firework shell and mortar tube failed during the show, leading to a blast that injured three members of the Central Maine Pyrotechnics crew.

Officers say 50-year-old Misty Mellor of Bath, an assistant working the display, was seriously injured and was flown to Maine Medical Center in Portland, where she’s still hospitalized.

Police say 34-year-old Jeremy Mitchell of Augusta, the lead technician on the show, was taken to Rumford Hospital, where he was treated and released, while 30-year-old Robert Bradford of Andover, another assistant, was treated at the scene of minor injuries.

No spectators were injured, and the remainder of the fireworks show was canceled following the mishap.

The cause of the malfunction remains under investigation by the State Fire Marshal’s Office.