A fire-breathing stiltwalker has suffered 'severe' burns to his face, neck and hands after a mask he was wearing caught fire.
The incident occurred during a dress rehearsal of Die Meistersinger von Nurenberg at the Lyric Opera of Chicago in front of a shocked audience.
Actor Wesley Daniel, 24, had set fire to alcohol in his mouth but his head and "fireproof" mask were also set alight.
Witness reports say he was engulfed in flames before staggering off stage and collapsing and being doused with fire extinguishers by theatre staff in the wings.
Daniel is being treated at Loyola Hospital.
A Lyric Opera statement said: "Daniel was performing a fire-spitting effect while on stilts. He was wearing a flameproof costume and mask."
The spokesperson said the "fire-spitting effect had been approved by the Chicago Fire Department" but that a decision has now been made to remove it from performances.
The accident happened just half an hour before the end of the five-and-a-half hour opera that is due to open on Friday.
Audience-member Edward Voci told ABC: "His head was engulfed in flames and he was centre stage and in a panic."
"He was trying to put it out and then moved as quickly as he could on stilts but then he had no choice but to just fall down."
Actor Mia Rehwalpt was performing on stage when Daniel caught fire. She said: "I saw his head get covered in flames and I didn't really know what was happening."
"When he fell on the ground from his stilts it was really scary because it made a really loud thump."
A photographer for the Chicago Tribune Jason Wambsgans, described the moment Daniel caught fire: “He blew one or two fireballs, and then it looked like he had spilled it (propellant) on his chin or his chest or something.”
Adding: “It kind of consumed him, and he was staggering across the stage and then fell off his stilts on the opposite side of the stage.”
The Lyric's spokesperson said: "Lyric's emergency plan was activated immediately. Trained fire guards extinguished minor flames immediately. The fire curtain was lowered."
Theatre staff called the emergency services and paramedics arrived within minutes.
After an investigation by the Chicago Fire Department lasting about half an hour the rehearsal was allowed to continue.
The performance was cut short and finished around 6pm on Monday evening.