The Champions League final between Real Madrid and Liverpool in Paris on Saturday was preceded by chaotic scenes.
Supporters from both clubs trying to get into the Stade de France were funnelled into narrow channels to have their tickets checked, causing fears of a crush.
As kickoff approached thousands of Liverpool fans were stranded outside. As they pressed against the perimeter fences, police used tear gas.
The problems raise questions about France's organisation of the 2023 Rugby World Cup and the 2024 Paris Olympics.
- What happened in the buildup to the match? -
The build-up had been calm, with tens of thousands of Liverpool fans enjoying their fanzone in eastern Paris and Real fans entertained in their own area near the stadium.
Tensions began to rise as the scheduled 9:00pm kickoff approached. Long queues of supporters began to build up outside the stadium several hours before kickoff as French authorities funnelled them into narrow channels to check every ticket.
With supporters still stuck outside the stadium, UEFA delayed the kickoff for 36 minutes.
More than a thousand fans were still blocked to the west of the ground. Increasingly frustrated, they began shouting "open the gate", according to an AFP reporter.
When youths without tickets tried to force their way into the ground, with a handful scaling fences, police fired tear gas.
"There was pushing and crowd surges so we responded with security measures," a police source said.
Liverpool fans were incensed at the police's actions, including Pete Blades, who said it brought back terrifying memories of being involved in the Hillsborough disaster of 1989, which cost the lives of 97 Liverpool fans in a stadium crush during an English FA Cup game.
"I'm really stressed, I'm a teacher, I never got pepper sprayed," Blades told AFP.
"I haven't done anything wrong, I'm not a threat. The police pushed me at the door, that wasn't necessary, a girl's nose was bleeding."
-- Were Liverpool supporters properly advised? --
Two security perimeters were in place at the stadium - the first 200 metres from the stadium concourse and the other with turnstiles that gave access to the stands.
Two neutral supporters' representatives from neither of the clubs involved said they believe problems were caused by the transport route Liverpool fans were advised to take to the game.
The main suburban RER train line that serves the stadium was affected by strike action so thousands of fans arrived on another line. The station they used had just four exits instead of 13 on the normal line.
"This led to compression and crushing next to the station," one of the supporters' representatives said, speaking on condition of anonymity, adding that there were no stewards to help people find their way.
However, the Stade de France organisers said a lack of staffing was not the problem. One souce said the first security perimeter had given way, leading to fans massing around turnstiles to the stadium.
-- What role did fake tickets play? --
UEFA blamed the delays at the turnstiles at Liverpool's end of the stadium on "thousands of fans who had purchased fake tickets".
"There were a lot of counterfeit tickets," a source close to UEFA said. European football's governing body had intended to use tickets with blockchain technology but yielded to a request from Liverpool "who asked to have 20,000 paper tickets", the source said. There were "photocopies, crude imitations, and others which were actually very well done".
Liverpool defender Andy Robertson said after the game that a friend he had given a valid ticket to was wrongly told it was fake. "It's not been well organised," he said. Some fans even reported having their tickets stolen from them.
Ronan Evain, executive director of the Football Supporters Europe group, said: "Fans without tickets is a known problem. It's the role of the organisers and the authorities to prepare for it. This should serve as a warning, because it could have been much more serious."
-- Did Paris have enough time to prepare? --
The final was only switched to Paris from Saint Petersburg when Russia launched its invasion of Ukraine in February, after the French Football Federation offered to step in.
UEFA President Aleksander Ceferin said in an AFP interview before the final he had warned his technical teams they only had three weeks to prepare. "That's not easy," he admitted.
"It begs the question of whether France is capable of organising events on this scale," Ronan Evain said. "We keep repeating the same organisation that has failed in the past."