Swooping low

Driving down to work today, past the airport, I saw something unnerving. Usually planes come in for a long approach over the bay from the southeast. I saw a jet airliner crossing the freeway east to west at low altitude -- say 800-1000 feet -- at a spot I've never seen a plane before. It banked low over Millbrae and headed for a landing on a runway in an approximately southeast-to-northeast direction. I have never seen a plane fly low over Millbrae (a small town across the freeway and slightly south of the airport) before. I wondered if there was some kind of emergency, but now, two hours later, I don't see any news reports about a flaming crash, so I guess things turned out OK.