A British-based acrobat plunged 100ft to his death, shocking thousands of festivalgoers in Spain who watched his catastrophic fall.
Spaniard Pedro Aunion Monroy, 42, was performing in a suspended cage at the Mad Cool festival in Madrid shortly before Green Day were to take the stage on Friday night (7 July).
Moments before the band made their entrance however, Monroy fell to the ground to the sound of screams from the audience.
But Green Day were not told about the fatality and performed their set as normal, only to find out after they had left the stage.
"We just got off stage at Mad Cool Festival to disturbing news. A very brave artist named Pedro lost his life tonight in a tragic accident," the band tweeted shortly after their performance.
After the fall, dozens of people took to Twitter to criticise festival organisers for allowing the performance to go ahead as scheduled.
"The show mustn't go on," Andi Yi tweeted. "Horrible, sad and disgusting."
Ignacio Martin said: "Shame on you Mad Cool Festival. You should have cancelled the event. I saw the guy die, you knew it well."
Organisers released a statement stating they were very sorry for the accident, but defended their decision to continue with the final act for "security reasons".
"Mad Cool Festival regrets the terrible accident that the aerial dancer suffered during the second day of the festival," a spokesman said.
"For security reasons, the festival decided to continue with its programming. We send our most sincere condolences to all his family.
"On Saturday, during the festival, we will render a heartfelt tribute to the artist."
Warning: Some readers may find the following video distressing
Monroy was the director of In Fact performing arts company located in Portsdale, Brighton.
His sister confirmed his death online, writing: "To all the friends of my brother Pedro Aunion Monroy. I'm sorry to tell you that he died today.
"He was doing what he liked most, a show at Mad Cool. We are torn apart."