Groundfires have no visual when under water, but do deal regular burn damage

Battle replay example - Pyros spawned at shallows and seafloor die, then ducks die to the invisible groundfires left behind.

https://zero-k.info/Battles/Detail/2485016

I had an experience with this on Canis River, some pyros died in the river, and I couldn't see the groundfire.

Something should show.