A player at a large paintball event in Canada loaded their gun with marbles instead of paintballs, according to police.

Canada's CTV News reports that last weekend's D-Day paintball match in Ottawa almost turned deadly because of the person's decision. The annual event apparently involves about 1,000 players from across North America.

At least two people told police they were hit by marbles during the event. One person was hit three times in the chest, knocking him to the ground, according to CTV News. Neither victim suffered any serious injuries.

Paintballs typically travel at about 160 to 190 miles per hour, according to various reports. That's much slower than a bullet, which travels about 1,700 miles per hour, but fast enough for a solid object like a marble to be deadly.

The event was canceled as soon as word got out about someone using marbles in their gun. CTV News reports that four marbles were found on the playing grounds.

Police aren't sure who's behind the incident and the company that organized the event is offering $1,500 for information that leads to an arrest.

Clint Davis covers entertainment and trending news topics for the Scripps National Desk. Follow him on Twitter @MrClintDavis.