The tragic death on Saturday of FDNY Lt. Gordon Ambelas was the first line-of-duty fatality for the FDNY in more than two years—since the loss of Lt. Richard Nappi on April 16, 2012—a period during which the department responded to more than 50,000 structural fires.
Exactly what happened in the Williamsburg building where Ambelas died won't be known for some time. The FDNY will do its own investigation with an eye toward explaining the death and deriving some lessons from it; the result will be a report like this one on the 1999 fatality that claimed Capt. Vincent Fowler. It's possible that the federal National Institute for Occupational Safety and Health will conduct its own investigation, as it did on the 2007 Deutschebank disaster.
Documents like those facilitated CityLimits.org's 2011 investigation of firefighter fatalities in New York City from 1991 on, which found that problems with water flow, communications, the variance in how long air tanks last, and collapses of floors and ceilings were common killers of the Bravest.
High-rise buildings (like the one where Ambelas perished) carry unique risks thanks to the distance between the fire and hydrants at street level, the inability of ladders to reach the fire from the outside and the role of wind.