Volcano

The Volcano was a volcano that would erupt before it was removed in the rebrand. When it erupted, it caused something gray to flood the ground, trap vehicles and kill any players touching them. This is possibly based on lahars, which are a violent type of mudflow or debris flow. When it started flooding, it can flood an entire interior of a single-story home, but partially flood the inside of a two-story house.

It's unknown what happened when a player went to the top of it while it was erupting, and possibly killed them.

Trivia

 * The volcano is one of the disasters that was removed after the rebrand, along with flash floods and earthquakes.
 * No lava flowed down from the volcano, implying that all of its eruptions were all phreatic.