Pool Chemicals Explode

pool chemicals explode
pool guys, listen up?

At what point is explosion likely to happen? I found a lid today that plainly said that if I added a chemical it might explode. This is different than what I’ve known. What’s up?
Alright, I know not to send the two chemicals down a trench and pretend it’s WW1. What I’m looking for is reality from you smart people who know chemicals.

it said it might explode they didt say it will so don’t worry

Man, Granddaughter Hurt When Pool Chemicals Explode