Burst Pipe - If this happens, shut off the nearest valve ASAP and mop/dry up as much water as you can. Then call someone for repairs.
Blackouts - Have available lighting (flashlight, candles) and if the blackout is prolonged, you need to disconnect your major appliances because a major power surge can happen and damage them all for good.
Gas Leaks - If you have a carbon monoxide detector going off, or smell gas, get out of the house and then call the gas company immediately.
Basement Floods - Don't just run down there to collect things that could get damaged. First, kill the power to the basement so you won't accidentally electrocute yourself, also wear boots or protective covering in case of sewage back ups or other chemicals that could be in the flood water.
Furnace Malfunctions - Sometimes it's an easy fix, check the air filter to see if it is in correctly, check the breaker to be sure it didn't just get tripped. Then call a repairman if those fail.
Kitchen Fires - First, with a lot of kitchen fires water is a no no because a lot are grease fires, so use baking soda to put on the fire. If it is in the oven CLOSE THE DOOR. Lack of oxygen can kill the fire.
Flushing Fail - First step is try a plunger. If that isn't it, take the top off the tank and check the mechanism inside to fix before you call a plumber.