Everyone talked about it on twitter. D:
Apparently, it was a prank...

If it was, it was a really awful prank. D:

"I have a really good idea for a prank, let's drag a canister of poisonous gas to a really concurred enclosed environment and break it!"

... it's not an awful prank, it's the equivalent of throwing bricks at someone with the intention of breaking their bones and call it a prank.

Yeah, honestly this is the first journal I've seen mentioning it!