3-D street art at the Promenade

Chalk artist Tracy Lee Stum cracks open the Grand Canyon into the middle of the Third Street Promenade (between Foot Locker and Armani Exchange) with three days of 3-D live sketching. The final, flat artwork, which appears convincingly dimensional from a particular angle, will be on view until Monday for photo ops—and a chance to win a trip to real-life, non-chalk Arizona.