I've seen it reported that in the current history of the New York fire department, starting in 1898, there have been a total of somethiing like 778 lost in the line of duty.

In two hours, they acquired another 350 missiing and presumed dead.

Stats are hard to come by, The talking heads are, well, talking heads, and most web sites seem big on sensationalism and low on background. I've heard from 250-350, but even the low end is... well, shocking.