Safety first.

That’s the idea behind Iron Maiden’s move to cancel a gig in Rio Sunday night when a barricade at the front of the stage collapsed due to a surging crowd of enthusiastic fans.

Terra reports the incident happened during the first song of the band's set at HSBC Arena in Rio de Janeiro, Brazil.

Opening with "Satellite 15...The Final Frontier,” Maiden’s lead singer, Bruce Dickinson, noticed the barrier separating the fans from the stage broke and the crowd had rushed forward towards the members of the group.

Dickinson urged the crowd to take it easy. "Hey guys, please calm down. Everyone, take a step backward. The fence broke and it's dangerous. We do not want anyone to get hurt," he announced.

A 10-minute delay to fix the barricade became 20, before Dickinson then returned to the stage to update fans. "The fence is completely broken. We do not want anyone to get hurt," he said, advising fans to pick up a bracelet before leaving the venue giving them access to tomorrow night's show. "We cannot play tonight, but tomorrow, at the same time, we'll be here," he added. "Everyone who has a ticket or bracelet will be able to enter. Those of you who cannot make tomorrow's concert will be given a refund."

A full makeup show at the HSBC Arena is confirmed for Monday, March 28. Here’s the statement from the promoters, Evenpro:

The Iron Maiden Concert at HSBC ARENA has been postponed to Monday, March, 28th due to technical problems with the barricade provided in front of the stage.

This decision was taken by HSBC ARENA in agreement with the band's staff, because it's their priority not to put fans' safety in risk.

Iron Maiden will stay in Rio de Janeiro one more day to be able to make the show and not leave Rio de Janeiro out of this leg of The Final Frontier Tour.