These were prisoners abandoned by guards as the flood waters rose. Some had to break out of their own cells, with the water chest-high; others descended to the lower levels of the jail to rescue other prisoners. And lest Bill Bennett and his ilk think this was just a matter of hard-core criminal scum getting no better than they deserved, Rich digs out this telling quote: "Some of these prisoners were in fact serving misdemeanor sentences, and others were picked up for parole violations, but the vast, vast majority of the prisoners being held at Orleans Parish Prison were pretrial detainees. They had only been charged. They had not been tried and convicted."
Of course, it wouldn't make any difference if they were all hard-core convicts; the inhumanity of abandoning them to the flood would be just as egregious. But we'll certainly keep tracking this story as it develops.