Go and see what is going on .
You mint have to do some thing about it.
go now before you find a flood.......
Wait til morning and you will have more damage than you care to look at. I would go now. But be careful if you have to stand in water.
Make sure you have some good rubber boots in case of electrical wiring in the water too.
ya i would go down now...
Anything on the floor that could be destroyed by water? Drain or no drain, if there is something that could be destroyed by becoming water logged, I'd see to it now.
So, go check; what could it hurt. You could rescue something or you could look around and decide it can wait until morning. Two minutes of your time.
If your hearing it from upstairs, you may regret waiting.
Good luck with it!
just huck a stick of dynamite down there and let the problem solve itself :P