Could be as simple as the colder water hitting the hot glass on the lamp. The glass may be cracked.

Here is a link that might be useful: definition

The glass was not cracked. Do you mean the wet wiring cannot but wet light bulb can cause the light going off?

Water can cause the breaker to trip (or perhaps an AFCI or GFCI depending on whether there is one on this circuit). It certainly can thermally shock the bulb as BUS says and the bulb can go even if the bulb doesn't obviously appear to be damaged.

If the fixture is dried out, you can try replacing the bulb and resetting any tripped breakers/GFCI/AFCI devices.

Is the fixture flourescent? If so, water may have penetrated the ballast housing and fried it.