1 knocked unconscious in San Francisco pillow fight

SAN FRANCISCO -- Valentine's Day in San Francisco means hundreds of people ditch date night for a little free swinging, feather-flying fun.

We're talking about the great San Francisco Valentine's Day pillow fight held in Justin Herman Plaza.

The free-for-all is a way for people to release anxiety or stress. Only problem is this year one person was injured when he slipped on some feathers.

Even though participants are encouraged to clean up after the fight, the city says it costs about $5,000 to sweep up all the feathers that come loose.