Chicago was unseasonably hot and dry in the fall of 1871.
The city had gone months without rain.
- And of course, the city is built so much out of wood.
- The streets are wood.
The bridges are wood.
It's so hot that the tar on some
of the roofs start to blister in the sun.
- [Narrator] The fire department consisted
of just 185 firemen in a city of 300,000.
They relied on horse-drawn,
steam-powered engines with little water pressure.
- The fire department had 20 fires
just in the first week of October.
So, they already knew that
the conditions in Chicago were bad.
- [Narrator] Each time a fire erupted,
a watchman in the courthouse tower
rang the five-and-a-half ton bell.
The night before Mrs. O'Leary's barn caught fire,
a planing mill on the city's west side went up in flames,
leveling four square blocks.
Firefighters quelled the blaze after 17 grueling hours.
Their clothing was burned, their eyes red and swollen.
- So, when you consider that those
firefighters were worn out, their equipment was damaged.
They were vulnerable.
- [Narrator] The next morning, William Bross' "Tribune"
made a prophetic warning,
"a spark might set a fire which
"could sweep from end to end of the city."
- Everything, all the wood,
all that combustible material was brittle.
It was ready to catch on fire.
It just needed a spark.
- [Narrator] Catherine O'Leary went to bed
that Sunday evening, October 8th at eight o'clock.
Her barn was stocked with fresh hay
and she was nursing a sore foot.
Through her thin bedroom wall,
O'Leary could hear her tenants, the McLaughlins,
welcoming a relative from Ireland.
- And Mr. McLaughlin, I guess, was a great fiddle player.
So, they were having this party, coming and going, dancing.
Mrs. O'Leary stated that she was having trouble sleeping
because she could hear all the noise
going on in the McLaughlin's house.
- [Narrator] I could hear from my own bedroom.
Could hear them going on.
There was a little music there.
Her husband was a fiddler.
- [Narrator] O'Leary had barely drifted off to sleep
when her barn began to burn.
What exactly triggered the blaze
remains shrouded in mystery, legend, and lies.
- The myth is that Mrs. O'Leary was out in her barn
and she was milking her cow
and the cow knocked over a lantern.
That's ridiculous, really, when you think about it.
Because nobody would be milking a cow
at nine o'clock at night.
- [Narrator] O'Leary said she had
no idea how the fire started.
- [Narrator] I ran out and the whole barn was on fire
and upon my word I could not tell any more about the fire.
- She just started crying and screaming.
I can only imagine how desperate she had to have felt.
- [Narrator] A watchman in the courthouse tower
named Mathias Schaffer spotted smoke
and the giant alarm bell was sounded.
- He got word out to the fire companies,
but he mislocated the fire,
so he sent the engines to the wrong place.
- [Narrator] His blunder was just enough
to give the fire a foothold.
Several engine companies arrived 45 minutes later.
But by then it was too late.
The blaze had consumed several blocks.
Some Chicagoans gathered to enjoy the spectacle,
unaware of the danger.
- People treated fires like entertainment.
There's a fire, let's go watch.
So, people were on their rooftops.
People were on their front porches.
People were out in the street.
- [Narrator] Joseph Edgar Chamberlin
was one of the first reporters on the scene.
It was the scoop of a lifetime,
but Chamberlin couldn't help but dismiss
the Irish immigrants he encountered.
"More casks of whiskey appeared," he wrote,
"and scores of excited men drank deeply of their contents."
- He calls them drunks, inebriates.
The women are harlots.
And after all, it was only the saloons
and the brothels and the barns
of the Irish immigrants that were burning.