Discovered a leak on our water heater around 8pm on a Friday night. Yikes!
Had to shut the water main off and call plumbers. Luckily, I remembered our HOA uses city wide for all plumbing issues. Their office didn't open until 8am the next morning (Saturday), but they had someone here by 10am. Fixed the issue (wasn't the actual water heater itself). Cost $180. Not too bad, I guess. Especially when you need water!