Fortnite blue white smoke from the ground?

I saw at Fortnite that sometimes blue and white smoke comes out of the ground. Does anyone know what that is? Apparently weapons can come out of it, too?

First of all my subjective opinion Fortnite is rubbish, but since I played it earlier, at the places where smoke comes a lootdrop in FN I just believe a balloon with a box. You should actually be able to see the balloon above the smoke.

Either it means that you should uninstall the game or that a lootdrop will land here.

But rather believe that the first is true.