Most items held in Security deposits are not insured or probably insurable.
Also. many items stolen in such cases is never reported to the police, for a variety of reasons, so often it may not be known just how much was really stolen in such cases.
Anyone who steals steals from 'all of us' one way or another. And the police, court, lawyers time, prison costs etc, comes out of our pockets.
Also, that people may not have been injured or worse is similar cases does not mean there were no plans for that to happen, should 'it become necessary.'