It looks like the videos have been taken down. I saw one earlier that was truly harrowing - blood everywhere, on the ice and down the front of the player's white uniform jersey, as the player was led to the sidelines by a teammate after having his throat slashed by an opposing player's skating blade.
If you didn't know better, you'd think it was a sacrifice.
There is an investigation going on:
https://sports.yahoo.com/death-of-hockey-player-adam-johnson-under-police-investigation-192539698.html
Not sure if it was intentional or not but from what I've learned is the other player is known for being perhaps the dirtiest player in that league...