1950 Oneida NY train wreck

In the first quarter 2016 Central Headlight, the cover story is the account of the October 1950 train wreck at Oneida NY. Sadly, the fireman was instantly killed and it tells us that the engineer inhaled a lung full of steam from a broken pipe, staggered onto Main Street, and collapsed. He died a short time later in the hospital. My understanding of the characteristics of high pressure, super heated steam is pretty much limited to the actions of my HO scale 12V steam locomotives. So what was it that made that lung full of steam so lethal? Was it the heat of the steam or was it because of the expansion of the steam after it got into his lungs? The caption under a picture of the overturned locomotive described it as: having inhaled "live steam", What is the definition of "live steam"? Is that steam that is still expanding?

Howard S

"Live steam" is steam under pressure, as opposed to vapors merely rising from heated water.
My best guess (being neither an engineer [meaning a guy with a degree, rather than a locomotive "driver"] nor a pulmonologist) about the fatal effects would be that the steam condensed due to the lower temperature inside the body (98.6° F vs. 212°+), resulting in fluid in his lungs.
I have seen something on the Interwebz about a woman who supposedly drowned from the steam produced by a shower in a closed room, but it's probably an urban legend. (Actual drowning occurs because the victim's glottis involuntarily closes to keep water out of the lungs, which prevents inhalation of air as well.) There was a scientific reply to the question about "steam drowning," which included this: "At normal atmospheric pressure, steam has a maximum (saturated) density of about 0.590 kg/m³. An average person breathes at an average rate of about 0.00015 m³/s. Most lungs have a total volume of 0.004 to 0.006 m³. So a person inhaling fully saturated steam, whose lungs are unable to absorb any water, would fully fill their lungs in about 15 hours. A steamy shower is less than fully steam saturated, so this time would be longer."
Again with no scientific knowledge to back this up, I suspect the steam from the locomotive either rapidly condensed into liquid, displacing oxygen, or maybe it didn't even need to condense. It was like probably also much like inhaling superheated gases from a fire, which can also cause edema from trauma to the respiratory tract.

My guess-- with at least as many disclaimers of expertise as Watchman318-- it that it has to do with steam being hot. Not just hot like what comes out of a teakettle (which is enough to give a painful scald) but hot like steam at high pressure: steam escaping from a ruptured locomotive boiler (or more likely ruptured pipes to/from a locomotive boiler would likely be well over 212F. Inhale two lungfuls of this and you would scald your lungs.
(But remember, this is a non-expert's guess.)

My aunt was on duty that night at the Oneida City Hospital as a nurse when they brought the engineer in. I guess it was not a pretty sight.