With just four days to go before the Inauguration, caretakers of the National Mall are rushing to preserve the grass.
Huge crowds four years ago virtually destroyed the grounds.
Starting Friday morning, crews will put down thousands of plastic sheets over six-and-a-half acres of new grass on the Mall.
The terraplas, as it's called, sits inches above the grass, allowing light and water to pass through.
This multi-million dollar project will take two days to complete.