Fan assaulted by security during Maple Leafs game.

An extremely disturbing video is making the rounds on social media, one that appears to show a National Hockey League fan being viciously assaulted by security during a Toronto Maple Leafs game over the weekend.

The video, which was published to social media site Reddit by user DescriptionMiddle723, shows a man being detained on the ground by a group of security guards when one of those same security guards suddenly begins dropping knees on the head of the defenseless man.

It is unclear why the man was being restrained but it's hard to imagine what he could have done that would warrant such a violent response from a member of the security staff.

Both the Toronto police as well as MLSE have both confirmed that an investigation into this matter is ongoing, but no further details have been shared with the public.

Several accounts on social media are making the claim that the man merely tried to exit through a private/secured door, although that has not been officially confirmed at this time.

I can only hope that everyone impacted by this disturbing incident is going to be ok.