Funnily enough, horses actually produce much more than 1 horsepower. I think the story goes that James Watt estimated it would take a team of 10 horses resting and taking turns to pull a tractor/mill/whatever that keep 2 horses constantly busy, so that's how he calculated it.
But over shorter durations, horses can produce much more.
A human can generate more than a horsepower, too, for short times. I used to have how fast you'd have to go up a flight of stairs to have done so.
However, Watt was a salesman, and intentionally misrepresented "mine pony power" as "horse power".
Some more honest ones state steady state in electric, but they are the exception.
He "mysteriously" disappeared. "They" did kill him.
But hundreds did die, and the tanks were used to roll back and forth over the bodies until they could be washed into the sewers. Your note is pedantically semi-true, and insensitive. It was a massacre scene.
