Plumbing break? Pull back the carpet and padding and look. Bummer.

weak bladder?

would think probably earthquake caused ground shift and a plumbing leak or crack in foundation that allows ground water to come up into carpet

you say "condo"
does that mean you own your unit?
how severe was the earthquake
anyone else having problems

We had that happen twice. It was a leaking water pipe under the slab. Had to jack hammer out the slab and get the pipe fixed. Call a plumber with special equipment that can detect leaks under the slab as leaks can travel and you want to locate the pipe leak, not where the water puddles.

We had a water leak in the wall in my daughter's bedroom . The wall had the water lines that connected to the toilet in the master bedroom. The leak was caused by the contact of copper waterlines on concrete slab. A chemical reaction between the copper and the concrete eats pin holes into the copper, causing the leak. Maybe that is what happened in this case.