Also, I would disagree (quite strongly) with the above recommendation. Carrying a fixed blade knife may not be possible in an urban environment but if you happen to have one at hand it will be a tremendous asset in a SHTF situation.

If disaster strikes getting hold of the right tools for the job is likely to be very difficult. A robust fixed blade weighs little, can be carried easily yet can take care of many different tasks. Including the heavy duty stuff such as prying doors, breaking locks, smashing car glass, removing rubble etc. This is where a sharpened prybar type of knife like the Cold Steel SRK, Gerber LMF or even the good old Kabar really shines. But I would take even a Mora over a multitool or folder any day for that kind of work.