${\mathrm{LiAlH}}_4$ violently decomposes in water to give:

Lithium aluminium hydride, or LAH, is a white solid, although commercial samples frequently turn grey due to impurities.
When it forcefully interacts with water, hydrogen gas is created. It should not be subjected to moisture as a result, and the reactions should happen in inert, dry environments. In the lab, hydrogen can be produced using this reaction.

${\mathrm{LiAlH}}_4+4{\mathrm{H}}_2\mathrm{O}\to \mathrm{LiOH}+\mathrm{Al}(\mathrm{OH}{)}_3+4{\mathrm{H}}_2$