The other night while driving my car, I hit bottom pretty hard comming out of a parking lot. Almost immediately, I started hearing a bearing knock, but only when braking hard. Next morning, I went to start the car, and there was no oil pressure at all. Any ideas on what I might have done?

Sounds to me like the oil pan got bashed up into the oil pickup tube. You are going to have to pull the pan off and have a look see.

Matt.