People who live in high risk areas will usually prepare for specific types of disasters, such as hurricanes in Florida. The rest of us mistakenly discount all such disasters as rare. In particular, fire is a most common calamity and can strike anywhere. Power at your wall outlet is supposed to be 120 volts. Some power problems can destroy equipment, but mostly the threat is loss of data.
Computers can fail due to either defects or age.
There is an old maxim in the computer industry that if a device survives the first 30 days of use, it will last forever. The thinking is that computer circuits, since they have no mechanical parts to wear, will either work or fail from the start. Low-end computers, which are built to minimize cost, can have failures at any time. This means theft of either hardware or software. Theft of software isn't very damaging if it's only copying the software.