I work in aluminum die casting. While working in Mexico, at one of my previous employers facilities, a small splash of aluminum fell on a pallet of scrap magnesium parts we used to maintain our aluminum within specs. The only way to calm a mag fire is to smother it. By the time I had it smothered, I had melted the tires completely off of our skidsteer, the whole back wall (30 feet) of our building was melted off and I nearly had to beat a fireman to death with his hose. 10 days later, the internal temp of the dirt piled over the magnesium was still over 1800 deg f.
Mag is very dangerous if not handled accordingly