Aqueduct

Three arches support the pipeline
Sending water to the city
I'm the one in the center
While the others are friends and family

The structure is upheld
By the keystone in the middle
The city's thirst is quenched
But then the keystone suddenly fails

And so the aqueduct totters
With a rumble and a shake
Will it all collapse
From such a rupture or earthquake?

But just when trying effort
Seemed but all in vain
Support, did they, the other arches
And I felt comfort in this pain