Okay kiddo, so in Avonmouth, which is a place in England, there was a really big boom that happened. Do you know what a boom is? It's like when you clap your hands really loudly. But this boom was really, really loud and it scared a lot of people.
The reason it happened is because there were some chemicals that were being stored in a big container. The chemicals got mixed together and there was a reaction, kind of like when you mix vinegar and baking soda together and it makes a fizzy sound.
But this wasn't a good reaction, it was a dangerous one that made a lot of gas and heat. The container couldn't hold it all and it exploded.
When something explodes, it can break things and hurt people. Unfortunately, some people were hurt in this explosion and it was very sad.
So now the people who take care of safety are trying to figure out how to prevent this from happening again in the future so that everyone can stay safe.