It's hard to process yesterday's deaths of 19 firefighters in Arizona. The tragedy is so stark an outlier that most states haven't seen that many deaths of firefighters due to wildfire in their combined histories. But there is one worrisome trend: fires are getting bigger and often deadlier.
The National Interagency Fire Center tracks wildfire incidents, scale, and damage for the United States. Included in that data is a list of firefighter fatalities through 2011, broken down by cause and county. No state has seen more firefighter deaths than California, which had 324 through that year. It is one of 11 states that has had more deaths than Arizona saw yesterday — with one of those states being Arizona. That largely tracks with this interesting map of fires by location. Most fires occur in the Southwest; many in California.
Over time, the number of firefighter deaths has been consistently low. Only two incidents on the NIFC's list were more deadly than yesterday's: a 1910 fire in Idaho and a 1933 blaze in Los Angeles. (This is only wildfires, of course. September 11th was the deadliest day for firefighters overall, and total firefighter deaths are declining.) But, as the graph below shows, there's been a slight uptick in deaths per year over the past few decades.