"No pants subway ride" sweeps nation

(CNN) - Hundreds of people were ready to leave their pants behind and jump on light rail at Westlake Center on Sunday. As soon as they got on, the pants came off. Many regular riders were stunned.

"We got on and everyone had their pants on," said Lauren Codington, a train rider. "As we started they definitely started to come off. We were confused. We were thinking they were going to take the rest of their clothes off."

It is the first annual "no-pants light rail ride" put on by Emerald City Improv. The drama group told people to act like any other passenger, but just without pants.

Word of the pantsless ride went viral in just the last week.

At one point in the ride, the underwear crowd tried taunting new riders to join in.