This reminds me of an event that occurred about 10 years ago, as I recall.
A plane overshot a runway, or otherwise went down in the water, outside an airport in a major eastern city; Boston, maybe.
The passengers survived the landing, but still had to get out of the plane in freezing water because the plane was sinking. I think they were getting into life rafts. An older male passenger, treading water, helped many of the the passengers get out of the plane in swirling river waters. He saved many lives, but after the authorities finally arrived to help, he was nowhere to be found.
This is the man I think of when I hear the word "hero".
I hope when I finally bite the big one, I can go out in a manner equal to this man's courage and sacrifice.