Nervous fans planning to attend next year's European soccer championship in 10 cities across France got a guarantee Sunday from the president of the organizing committee that security will come above everything.

"I've said it several times before: security is the biggest thing at stake for Euro 2016," Jacques Lambert said in an interview with sports daily L'Equipe, published in the aftermath of Friday night's attacks in Paris that killed nearly 130 people and left hundreds more wounded.

"I'm shocked by the cost of lives, which is terrifying," Euro 2016 committee president Lambert said. "But unfortunately I'm not completely surprised."

There is speculation that the tournament — France's biggest sporting event since the 1998 World Cup — could even be canceled for safety reasons. While acknowledging that "anything is possible," Lambert was adamant that this should not happen.

"Anything is possible, anything is conceivable," Lambert said. "But it would be to admit that for those who attacked us, it was worth it."

Euro 2016, uniting 24 teams, should be the pinnacle of soccer featuring the very best of Europe's talent, but a guessing game is now underway as to just how safe it will be with Lambert conceding "no one can pretend to be able to stop actions like this 100 percent."

Even if each stadium is secured, there's concern over fan zones in each of the 10 cities where supporters will gather to watch games on big screens. Millions will use these zones during the tournament's 51 matches, potentially offering 51 opportunities for terror to strike again.

Lambert spoke with suspended UEFA President Michel Platini after the attacks.

"(Platini) expressed the need to face up to this by taking the time needed and by giving ourselves the means to learn from all that has happened," Lambert said.

The series of attacks began Friday night to the sound of explosions outside Stade de France, where France was playing Germany, and where it won the 1998 World Cup final against Brazil in a joyous atmosphere so far removed from the darkness now overpowering the City of Light.

The stadium, which hosted the world athletics championships in 2003, will have the Euro 2016 opening match on June 10 and the final one month later. Security will be intense both in and around the stadium following reports that at least one of three suicide bombers tried to access the Stade de France on Friday before being prevented by security.

High-profile figures inside the stadium included French President Francois Hollande and the players themselves: World Cup winners from Germany and big-name club players like France's Paul Pogba, one of Europe's brightest talents with Juventus. Add to that 80,000 fans.

As the carnage unfolded in Paris, with six gun and bomb attacks over the course of 20 minutes in areas of the capital packed with people, the national team's players kept playing, unaware of the mayhem. TV commentators covering the game did not mention the events — aware that the message could be quickly relayed back to fans and cause confusion and panic.

"(It was) like a nightmare and a tragedy. I wasn't at the Stade de France, or in Paris, so like most French people I followed the events on television," the 67-year-old Lambert said. "I felt a great shock and a lot of emotion."

Lambert said "a wise decision was taken not to stop the match," praising fans for leaving the stadium calmly at the end, as if people knew they had to stick together.

Then he spoke with Platini.

"I've spoken to him several times, Friday night and Saturday," Lambert said. "He's very hurt by it. He felt a sentiment of dread and he feels compassion toward the victims."

As athletes around the world, from the hot tarmac of the Brazilian Grand Prix to the cool basketball courts of the United States, paused to reflect on the devastating carnage, sports daily L'Equipe's front page on Sunday was a poignant and solemn one: a heart-shape of candles under the headline "En Deuil" (In Mourning.)

How to keep stadiums safe will be of paramount important in the months leading up to the tournament, but protecting crowds as they arrive was already problematic enough, given the need to keep rival fans apart.

Lambert says France was on alert before, given what happened in January when the massacres at Charlie Hebdo magazine and a kosher supermarket killed 20 people, including three shooters.

"Unfortunately it's a risk we've been living with for a number of years and especially the last few months," Lambert said. "We knew attacks on a major scale were going to arrive one day. When? We didn't know. And no one thought it would be (Friday) night."