ST. LOUIS — The professional wrestler known as The Undertaker got minor burns on his chest and a scare during a pyrotechnics mishap he escaped without serious injury.

World Wrestling Entertainment spokesman Robert Zimmerman said Tuesday that the wrestler, whose real name is Mark Calaway, is fine and suffered only a minor injury. In fact, he wrestled after being burned Sunday night during a live pay-per-view event at the Scottrade Center and was back in the ring for WWE's "Raw" show on Monday.

The Undertaker, one of the most popular pro wrestlers, enters the ring as fireballs explode and music blares. On Sunday, a fireball went off too close to him.

"It was a mistiming," Zimmerman said. "He threw his jacket down. It kind of singed is the best way to describe it."

The wrestler was evaluated by a ringside physician. Zimmerman said he suffered a chest injury that looked like a bad sunburn. He was cleared to wrestle and performed for 25 minutes.

It wasn't clear if the audience knew Calaway was really on fire or if it was part of his act. The Undertaker has notoriously disappeared from WWE for months at a time, often under the presumption that he is dead, only to mysteriously return to the ring to seek vengeance against those who have wronged him.

The pyrotechnics are operated by a company that contracts with WWE, not the Scottrade Center. Zimmerman declined to identify the company. A Scottrade spokeswoman did not immediately return phone messages seeking comment.

WWE is investigating to determine how the mishap occurred. St. Louis fire officials also are investigating but declined to comment. Bill Zieres, deputy chief of the Missouri State Fire Marshal's Office, said state officials have not been contacted.

Indoor pyrotechnics have become more common in recent years, especially at sporting events and concerts. In February 2003, 100 people were killed when pyrotechnics used by the rock band Great White ignited foam used as soundproofing around the stage at The Station nightclub in West Warwick, R.I.

But Zieres said injuries from professional pyrotechnics are rare.

"Most are done by trained and qualified professionals and are relatively safe if codes are followed," he said.

Other accidents have occurred at wrestling events.

In 1999, World Wrestling Federation wrestler Owen Hart, 33, was killed when he fell 50 feet into a ring as he was being lowered from the ceiling of Kemper Arena in Kansas City, Mo. The audience had no idea Hart's death was real — not just a stunt — in large part because the show continued.