For some reason when talking about 72-hour kits, most people seem to imagine themselves running with their family and kits into the mountains or surrounding areas. However, when I tried to think through our own actual risks, I couldn't imagine a single situation where running with a kit would be necessary.
During an earthquake, I wouldn't want anyone running anywhere. Afterwards, we would proceed carefully to retrieve our kits. During an approaching wildfire or hurricane, you would just need quick access to your kits in order to move them into the car for evacuation. Short of a war-type situation, I just can't see any reason that you would be running long-term with your kits. In a raging fire, tsunami, mud slide or tornado, you wouldn't even want to delay an extra second to grab a kit. In those cases, you just get out of the way as fast as possible.
I recommend that you do a risk assessment to help you plan what to put into your 72-hour kits? When you know your most likely emergency situations, you can include items customized for those moments. For example, here is an assessment of risks for our family (you can use the same list to evaluate needs for your family which will likely be different):
Tsunami - No risk
Hurricane - No risk where we live.
Volcano - No risk.
Mud slide - No risk.
Riots - Low risk.
War - Low risk. Evacuate to extended family outside of state/country.
Terrorism - Low risk.
Tornado - Little risk where we live (shelter in basement if needed).
Flood - No risk where we live. Possible risk for interior flooding. Would stay with extended family.
Nuclear - Evacuation unlikely as there are few escape routes available and they are likely to be jammed. Safer to shelter in home.
Fire - High risk. Speedy evacuation required. If required, we would evacuate to stay with family. Biggest needs: Change of clothes, underwear, credit cards, cash, etc.
Earthquake - High risk. Speedy evacuation may be required if there are gas leaks and/or fires. Three possible evacuation locations. Stay with extended family if they are not affected. Even in large earthquake, we would likely be able to access our supplies in our home (though it may have significant damage). Husband and sons would likely be involved in clean up and rescue. Biggest needs: Shelter, food, clothing, tools.
My family's biggest risks are fire and earthquake. I try to make my 72 hour kit reflect those most-likely situations.
In a fire situation, we will still have easy access to food and shelter. I know I'd want something to wear that I felt comfortable in (not cut-off sweats) as we would likely be assessing damage and cleaning up in the next few days.
Customized 72 hour kit: includes comfortable clothing and underwear. Cash and/or credit card.
In an earthquake scenario, I realize that most earthquakes have damage limited to a specific area. It is likely that our extended family would be able to come and get us if needed, but that might take some time. Our home is earthquake-prepared as it has been fastened to the foundation and is wood construction with limited masonry. Even in a worst-case earthquake, we would likely be able to use our home as a shelter. However, there are accompanying risks of gas leaks and fire. Those would require full evacuation. In that situation, we would likely end up in a shelter if available (which might take a day or so to locate) or in a field below our home. More likely, though, we would shelter in our home or yard.
Customized 72 hour kit: Food that is calorie rich so that we have the energy to help with rescues and evacuations, food that is familiar to the kids, clothing that is comfortable for work, gloves, tools including a crow bar, flashlights, whistles, cash, tarps, communication, radio, etc. We also need cold-weather gear located in an easily accessible space. These kits don't have to be light as I don't anticipate that we would be walking far enough that we couldn't return and get more.
Customized Extra kit: For my husband which he keeps at work. My main thoughts are that he would likely be walking home. His kit ideally reflects that specific need and would include 1 days worth of food, spare shoes, flashlight, cold-weather supplies and minimal shelter. His kit needs to be light-weight. We keep similar kits in each of our cars.
What are your family's biggest risks? How can you customize your 72-hour kits to be ready for those situations?