I have a 2010 Buick Lacrosse CXS 3.6 with 75,000 miles which I rarely drive anymore, but is running fine when I do drive it. I brought it into my garage today to do an oil change, etc. I was doing a preliminary look underneath with a flashlight, and I noticed a leak starting right there. It is coming off the frame rail just inside the passenger side wheel, and appears to be hydraulic fluid. I went back and checked the driveway, and no sign of a leak there, so I"m pretty sure it just started when I parked in the garage. I went through anything I knew of to check. The trans fluid has a dipstick and it seems to be fine, and the power steering fluid looks OK. I can't see any fluid in the brake fluid reservoir, however. Is this a brake line that just broke? If I refill the reservoir can I safely get to a shop a couple miles away?
Do not refill, and do not drive until you find the leak.
You cannot drive a car with brakes that only work on one side, or you'll end up in a ditch, or worse.
Vibration, wayward gravel and rust can cause sudden, unexpected brake line failure. That's why cars since the early 60's have dual-diagonal brake system so two wheel's brakes work even if the other part of the system has failed ( still not safe to drive).
Be glad your brake line broke on your driveway and not on the freeway.