Dozens of people among the crowd at the Bataclan concert hall on Nov. 13, 2015, had no idea what raucous sounds they were hearing outside the theater. Some assumed the loud noise was an amplifier or some other sound effect.

Within moments, it would become clear that the booming sounds surrounding the venue were that of bombs set off by Islamic State extremists about 9:20 p.m. as a France vs. Germany soccer match played at the nearby stadium. One person was killed from that suicide bombing. As the night went on, gunmen continued the attack, which eventually claimed the lives of 130 and injured more than 350.

Arthur Dénouveaux, who flung his body to the floor of the theater as the gunshots rang out that night, told Time he used his skills in the French military to inch his way out of the savage scene. He witnessed several young people make the same attempt unsuccessfully. Despite surviving the harrowing experience, the moments of that evening have never left him.

“When November comes, my sleep is really not good. I wake up tense and nervous,” he said. He has yet to see another live concert.

On Friday, a silent memorial took place in Paris to honor the survivors and those lost in the inexplicable attack targeted at the concert hall, Paris cafés and the national stadium. The series of coordinated attacks over more than four hours were the country’s deadliest during a peacetime. The unforeseen massacre forever changed Paris, with Paris military action against extremists intensifying and crackdowns on security becoming the norm.

The question that lingers for many as they observe the anniversary is why the attacks happened. Some of those answers may have been lost when seven of the nine terrorists accused were found dead after the massacre. One day after the attacks, ISIL claimed responsibility for the bloodshed, stating it represented the “first of the storm.” Police would issue hundreds of raids in the days following. The primary discovery was that of the vehicle, a black SEAT hatchback, that had been linked to the restaurant attacks and a litany of artillery found.

The unsettling truth for some was that the extremists were not foreign terrorists parachuting on the calm, cosmopolitan community. Instead, they were young European men, some from Belgium, who hailed from neighborhoods outside of Paris. The victims were their peers.

“It was an attack on youth culture,” said David Fritz Goeppinger, who was 23 that night at the Bataclan. He was one of 10 concertgoers taken hostage for 2 ½ hours during the final assault on the Bataclan.

“We are free to drink alcohol, to go to concerts,” he said. “It was a direct attack on young people who could do that.”

Nightmares of the attacks

For many, the senseless loss of young lives changed the carefree, tranquil energy of that neighborhood to that of a militaristic and disquieting one that would never quite return to its innocence. Many who survived report living with post-traumatic stress disorder. Now armed soldiers patrol train stations and tourist sites like the Eiffel Tower.

Denis Peschanski, a historian who has monitored the experiences of 316 survivors as part of a long-term study funded in part by public research agencies, said that up until last year, “more than 50% still had PTSD.”

Some of those assessed during the study told researchers they experienced flashbacks of bloodshed or bodies in their thoughts on repeat. Others say they now avoid public transportation, and they sidestep the neighborhoods where the attacks occurred, Peschanski told Time.

Dénouveaux, who serves as the president of a support group for victims called Life for Paris, said his response now is to “live life to the fullest.” He quit his banking job and decided to run an investment company of his own, in part, to avoid the constant glare of pity he was experiencing at his job.

“People were wondering how damaged I was,” he said. “I could see it in their eyes.”

In an unfortunate turn of events, Paris had to face yet another attack just weeks before observing the deadly attacks of 2015. In September, four people were killed there when three Islamic extremists assailed victims outside the former headquarters of the French satirical magazine Charlie Hebdo. The stabbings happened near the same area where an Islamic extremist attack took place in January 2015, which left 12 dead and 11 injured.

As for justice prevailing, a trial is set for two of the suspected planners of the killings for September 2021, which may bring some closure for the loved ones and victims still reliving that day.

“It is a horizon for us,” Goeppinger told the publication about the possibility of convictions. “It will be very powerful to stand there, and see those people who did this, and look them in the eye.” Do they hope to hear expressions of regrets from those in the dock? “No,” he says. “We do not expect remorse.”