What happened at the Bataclan?

A black Volkswagen Polo pulled up outside the Bataclan concert hall at 21:40 (20:40 GMT) on Friday 13 November, and three heavily armed gunmen got out. Less than three hours later they were dead, having killed 90 people at the venue and critically injured many others. What happened in between?

"It looked like an abattoir," Michael O'Connor, a 30-year-old from South Shields in north-east England who survived the attack, told BBC Radio 5Live. "I was wading through blood. It was a centimetre deep in places. I had to clamber over dead bodies to get out."

The gunmen entered the building through the main entrance about 30-45 minutes after rock group the Eagles of Death Metal had begun their performance. Witnesses reported seeing bodies on the pavement near the doorway.

Once in the building, they fired into the crowd. Their first move was to shoot everybody standing at the bar, witnesses Gregoire, Thomas and Nicolas told Liberation newspaper.

The trio had been watching the concert from the balcony, and recalled seeing a movement in the crowd below "like a gust of wind through wheat" as people began to realise what was happening and scrambled away from the killers.

Another spectator, Fahmi, was in the crowd on the lower level when he heard a noise he took to be firecrackers. "First of all I thought it was part of the show, but then I turned around and saw someone who had just taken a bullet in the eye," he told Liberation.

Many people dropped to the ground, but there was little cover in the concert hall. The gunmen shot at random into the mass of people lying down.

It seems that at least one of the gunmen climbed the stairs and killed more spectators on the balcony, possibly using this as a vantage point to take shots at others below.

Amid the confusion and panic, a security guard shouted for everyone to follow him through an emergency exit to the left of the stage, according to Anthony, another survivor who spoke to Liberation.

Many people made it out this way, some badly hurt, their traumatic exits recorded on mobile phone footage recorded from an upper window in an apartment on the opposite side of the street.

Julien Pearce, a journalist with Europe 1, a French radio network, lay down on the ground near to the front of the stage for about 10 minutes while the attack continued.

During a break in the shooting, as the gunmen reloaded their weapons, he encouraged a group of about 10 people around him to attempt an escape, jumping up onto the stage.

"We took refuge in a little room to the right of the stage, but unfortunately it didn't lead anywhere. We were trapped." They waited for another break in the shooting and ran across the stage to the emergency exit on the other side, Mr Pearce lifting a badly injured woman onto his shoulders and carrying her out.

According to Gregoire, Thomas and Nicolas, about 50 people found a way up onto the roof, staying there for more than two hours until the police operation had finished. Others hid in offices or locked themselves in toilets, waiting for help to arrive.

But many concert-goers had no option but to stay put, amid the dead and injured.

"I pulled my girlfriend underneath me and I lay on top of her," Mr O'Connor said. "There was someone on the bottom of my legs, there was someone lying on top of my girlfriend's head - it was a real squash. There were people who were unconscious or terribly injured - I think they were dead."

Mr O'Connor feared the worst. "I told my girlfriend that I loved her - what else can you do in that situation?"

Theresa Cede told the BBC: "One guy was badly hurt, and moaning, so we tried to say: 'Shh, be quiet, stay alive and don't move,' because every time there was movement somewhere, there were more gunshots."

After what Ms Cede said felt like an eternity, the police arrived.

A senior officer from the anti-crime branch and his driver were the first to arrive. They shot at one of the gunmen, who blew himself up.

The officers then retreated. In the foyer they crossed paths with a team of heavily armed officers making their way to the concert hall.

The team from the BRI (Brigades de Recherche et d'Intervention) unit, which specialises in hostage situations, made slow progress.

"There were bodies, people hidden in every nook and cranny, phones vibrating, and blood, a lot of blood," one officer recalled, according to RTL, external.

"We got out those we could."

Michael O'Connor said: "I could see the entrance to the arena behind us. I saw the door slowly open. I didn't know what was coming through - then I saw torches, flashlights, and I thought: 'It's got to be the police.'

"They were behind big bulletproof shields. They didn't say anything, they were motioning us to stay still. They formed a perimeter at the back of the hall and they pointed guns at the balcony, where the terrorists still were."

An hour after entering the concert hall, BRI officers reached a door on the first floor.

A voice behind the door - a concert-goer being held hostage - told them there were two men holding them, each with an explosive vest.

"You can thank President Hollande, because it's thanks to him you're going through this," the attackers had been telling the hostages, according to one of those held who spoke to L'Humanite, external.

They were made to stand in front of the doors and windows, and act as go-betweens with the police.

The police were passed a mobile number and spoke to the attackers several times before midnight.

Negotiators concluded the men intended to massacre their hostages in front of the media, and the order was given to attack.

Police union spokesman Nicolas Comte said officers entered and advanced behind a metal shield, which was hit by 27 bullets.

"The officers realised they had to finish things quickly. They managed to shoot one and soon, as he saw that, the second one blew himself up."

The siege was over, but the marathon task of saving the lives of those who had been critically injured was just beginning.