The Stone Bridge

The stone bridge was around for century's or more.
It held foot soldiers, horses and carts in days of yore.
Now it’s cars and trucks, a common sight you saw.
One night with no fright a stone fell out of sight.
Next day two stones dislodged and fell away.
More stones fell, why you just couldn’t tell.
Stones in time dislodged without reason or rhyme.
If an engineer looked at the bridges fate.
He’d know the bridge had a used-by-date.
But cars and trucks just went their way.
Then without a prompt the old bridge just fell away.