iPhone suddenly showed some sparks in the screen

I was calling my friend when all of sudden the screen shows some spark with the typical fireworks spark sounds. It comes from the bottom of the screen and going up like fireworks, it happens like in a split second I thought it was my friend using a filter but after that my phone can't work and restart itself.

Before this, I put my phone in my pocket when i was working but it was suddenly raining so I don't really have time to put it away

Does anyone know anything?