Back in late January, I was one of the first responders to an "explosion with injuries" call. (It was later determined to be a home that had exploded, in which two people were severely injured and one 15 month old infant died in the resulting blaze.)
One of the very first things I noted on arrival at the scene was a strong odor of gas. We had to immediately evacuate neighbors from the area. They had NO TIME to grab personal possessions from their homes, they had to run, NOW! They couldn't even get in their vehicles to escape, they had to hoof it as quickly as they could and dressed as they were. (It was later determined that where I stood to photograph the initial shots of the scene, in front of one of the evacuated homes, was greater than 95% saturated with natural gas. Sorry, my photos are unavailable as they are being used as potential criminal evidence.)
That tells me a few things to note to my readers...
A. Be prepared to bugout on an instant's notice. Don't argue with or question the emergency response personnel, follow their direction immediately. Make a plan to bugout and practice the bugout. Have available a bugout bag, which is a a bag of essentials that you'll need for a day or three until you can muster assistance. Keep that bag where it can be grabbed immediately on exit. At an absolute minimum, your bag should include:
1. Clothing geared towards seasonal conditions.
2. A toiletry bag of essential personal hygiene items you use daily.
a. Consider adding a pair of shower shoes for sanitary purposes.
3. A computer flash drive containing prized photos, phone numbers and addresses of important contacts, insurance information, etc; so that you can recover those items from another computer. The drive should be password protected for security purposes. Use a password that you won't forget. You may want to further protect the flash drive by placing it in a waterproof, crush resistant, lockable container like an OtterBox 1000.
4. Personal medications that you need daily.
5. Spare personal items that you use daily that may have been left behind because you couldn't get to them. (My personal examples of this category would include a Swiss Army knife, a good LED flashlight, a good pen, a stainless water bottle and a bandana.) If you're packing for a child or pet, don't forget some mind occupying/comforting toys for them.
6. Cash and/or a prepaid debit/credit card.
7. Spare keys / keyring.
8. You may want to include wilderness survival essentials if your bugout plan requires extensive travel or travel to or through remote areas.
Strive to keep the prepared bags as light as possible. Twenty pounds doesn't sound like much weight until you've had to tote it all day. Think minimalistic. It may be helpful to take notes for a day or two as to just what you really do use on a daily basis.
B. Install early warning devices in your home. Carefully follow the manufacturer's directions for installation of the devices.
1. You should have a carbon monoxide detector on each level of your home that has a fuel burning appliance AND one within 15' of each bedroom.
2. You should have a smoke detector IN each bedroom and on each level of the home.
3. You should have a gas detector on each level that has a gas fired appliance.
C. Don't ignore potential danger. If you smell gas and/or if an early warning device alarm sounds; grab your bag, get out and retreat. Call 911.
The bottom line is this - you don't know how or when an emergency situation will occur which might require your evacuation. "Failing to prepare is preparing to fail."