Authorities investigating how a circus performer fell to his death during a performance Monday in front of thousands of spectators are focusing on the integrity of the equipment.

The fall took place about 6:30 p.m. under the big top of the traveling circus that was set up in South El Monte, east of downtown Los Angeles.

The Los Angeles County coroner's office identified the dead man as Roberto Valenzuela, 35, of Brownsville, Texas. It said he had been performing for 10 years, four of which he had spent with Circus Vazquez.

Officials said Valenzuela's routine involved a long red drapery suspended from high up in the tent. During the routine, Valenzuela fell to the ground, striking his head. He was pronounced dead at the scene from massive head injuries.

In addition to the drape, officials recovered bolts, although it was not clear where they came from. Investigators said Valenzuela set up his own equipment.

The incident was being investigated by the Los Angeles County Sheriff's Department and Cal/OSHA.

Dean Fryer, a Cal/OSHA spokesman, said the investigation was focusing on the integrity of the equipment used in the performance.

"In any workplace where you are performing job duties above ground, you have to have some sort of fall protection," Fryer said. "The question here is, was it being used properly, was it maintained properly, and why did it fail? That's what we are going to look at."

By ANDREW BLANKSTEIN

Los Angeles Times