People joke about a fire drills at work or their neighbour in the apartment building burning the toast and setting off the alarm. We don't equate that to people laughing about dozens of people burning to death (even if that's a possible reality of a fire) because to most of us it's not conceptualized like that.

This is a teacher in the US who would have had to sit through live shooting drills and never believed a live shooting would happen at her school (How much would you need to be paid to work somewhere where you seriously believed you had a 1 in 100 chance of being shot in the next 5 years, it wouldn't be a teachers salary for most of us).