in the early 90s when i was a navy corpsman at balboa, they held the 1.5 mile pft test on the balboa stadium track. a bunch of us had to escort the active duty nurses and corpsmen to the track because bums were harassing the runners the year before. we were very menacing in our navy dungarees and no runners were harassed that fine san diego morning.
i guess the neighborhood hasn't changed much - where anything not welded down is stolen and sold for scrap.