A referee was injured Saturday at Maine Maritime Academy when a cannon blast set off from behind the end zone hit him in the head, according to the Hancock County Sheriff’s Office.

It’s academy tradition to sound off a cannon using a blank shotgun shell whenever the team scores, according to the sheriff’s office. But authorities said an alumnus of the school who brought his own cannon to Saturday’s homecoming game against Massachusetts Maritime Academy had loaded it with black powder and “a substance that he had made into a wad.” The referee was struck by the wad and taken to a hospital with non-life-threatening injuries.

The incident was captured on video and posted online by local media. The referee is shown walking near the edge of the field during the game’s second half. When the cannon is set off, he immediately grabs his head and collapses to the ground.

The school said in a statement that the cannon, owned and operated by an alumnus, “was fired from outside the fence behind the end zone. One of the game officials was proceeding along the end line when the cannon was fired and was struck by packing material from the cannon. The Academy’s president has directed that these devices will no longer be permitted on campus for future events.”

The sheriff’s office said an investigation into the incident will be referred to the district attorney’s office pending potential criminal charges.

Maine Maritime Academy lost the game to Massachusetts Maritime Academy, 42-21, according to the school’s website.