CHICO, Calif. -

It was a thrilling day in downtown Chico.  For the fourth year in a row, dozens of people dressed up like zombies to dance to Michael Jackson’s “Thriller” song.  They performed at the exact same time as 173 other groups around the world.

The worldwide event is called “Thrill the World.”  It started at noon Pacific time.  At that exact moment people were performing the same moves at all the sites registered around the world, from the U.S. to China.

Chico’s City Plaza was jammed with about 250 dancers.  Hundreds of spectators crowded into the plaza to watch what’s becoming an annual Halloween tradition.

The group called "Thrill The World Chico" has been holding weekly practices for five weeks to teach people the moves and improve their synchronization.