You bet. There have been cases where an airplane has crashed on an airport at night in the middle of the city, and no one noticed until the tower opened in the morning.
Locally, someone could go down in Coyote Hills and no one would notice unless they lit the hills on fire.
It's a lot harder to find a wreck than people think, even with an ELT. And ELTs in a warehouse are painfully difficult to DF. Every bit of steel reflects the signal. Hell, I've had fun chasing them at Reid due to the baseball diamond's chain link fence. And the one time I set a practice beacon at South County (in the museum), there were false signals all over the airport. The poor guy I was exercising ended up looking in every dumpster, and it wasn't in any of them.
ELT's reflect off of lots of stuff. Transmission lines are the worst. But even a tiny bit of terrain or a few trees can make them really hard to find on the ground. It's easier in the air.