A section of Estadio Monumental in Chile has collapsed whilst containing masses of Colo Colo fans.
The stadium, which holds over 45,000, was hosting an opening training session but several fans are now feared injured. Supporters had gathered inside the arena to celebrate 33 years since the stadium opened.
The team were preparing for a match with Catholic University, due to take place on Sunday, but the incident saw training curtailed.
"We saw it from a distance and we are going to get closer to see what happened and if it is necessary to provide help, if there are injuries," the former president and current member of the social club, Edmundo Valladares, told Radio Bío Bío.
Accidents, which included a fatality in 1993, saw the stadium modernised and meant the capacity had to be reduced to its current capacity of 47,000 spectators.
The Estadio Monumental was used for two Copa America matches back in 2015, when Chile were hosts, with Brazil featuring on each occasion.
Maximiliano Falcon, who plays for Colo Colo, and has previously been named in a Uruguay squad, commented on the situation: "When we went up there was a comment that something had happened. If something happened, I hope you are well. Second, what has been said repeatedly, was said by several players from other clubs, insist that people behave.
"That on Sunday people come to cheer, that they enjoy this. Personally, it makes me a little angry to insist that people don't do that, that they behave well, sometimes it's a bit tiring when they don't. It is for them and for us that we need all the parties to be present. I hope it doesn't happen again."