"There was blood everywhere. Even people alive were covered with blood," he told reporters. "There was especially on the ground floor a lot of dead bodies and blood, and some people had been alive and had to stay for several hours among dead corpse[s] and they went out covered with blood."
Plaud and about 15 others hid for three hours in a small room upstairs of the theater, struggling to keep quiet. The sound of machine guns was so close it shook the walls, he said.
Downstairs Julien Pearce, a radio reporter, was near the top of the stage when the shooting began.
He saw two people, terrorists, he said, enter the theater, "very calm, very determined" and firing "randomly."
They wore black clothing but no masks. He saw the face of one shooter, who was very young -- a maximum of 25 years old.
"He was like a random guy holding a Kalashnikov. That's all."
Pearce said the gunmen stood near the back of the room and continuously shot people who had dived on the floor when the shooting started -- shooting some of them execution-style.
"They were not moving," he said of the gunmen. "They were just standing at the back of the concert room and shooting at us. Like if we were birds."
"It was a bloodbath," Pearce says.
"People yelled, screamed," he said. "It lasted for 10 minutes. Ten horrific minutes where everybody was on the floor covering their head."
At least 80 people were killed in the attack at Bataclan, the the Paris prosecutor said. Earlier, the French interior ministry said 112 were killed there. In all of Paris, the attacks left at least 129 dead and more than 350 people wounded authorities said.
The theater has a capacity of 1,500, Cyril Vanier, a reporter with France 24, told CNN.
After police entered the Bataclan, detonations and gunfire could be heard from outside the concert hall, according to a CNN producer at the scene.
Four attackers were killed in the raid -- three of whom were wearing explosive belts -- according to Michel Cadot, a Paris police prefect who was interviewed on France Info radio.
Authorities were able to bring out at least 100 hostages, some of whom appeared to be wounded.
More than 40 people were killed
in other attacks elsewhere
in Paris and in Saint-Denis, French officials said.
'Stay still, keep calm'
Plaud was dancing when he heard a loud noise around 10 p.m. (4 p.m. ET).
"I thought it was a bad joke at first, but then there was something not natural, I don't know, it's difficult to explain. I just left all my things and tried to get somewhere, where I could wait.
He ran into a small room where others has fled.
"There were some women inside and they were panicking, so we tried to say 'OK, stay still keep your calm' and we waited and tried not to make any noise," he said.
'Hide and play dead'
Pearce says he told the people around him to hide and play dead.
They waited until the gunmen reloaded their weapons and ran to an empty room, which didn't have an exit.
"We were trapped," he said.
After five more minutes of gunfire, the attackers stopped shooting. "They reloaded again, and we ran."
Pearce found an exit and ran to the street.
On his way out, he encountered a teenage girl who had two gunshot wounds in her leg and was bleeding very badly.
"I grabbed her, and I put her on my back and we ran."
After going about 200-300 meters, he put the girl in a taxi and told the cabbie to get her to the hospital.
When he reached the street, he saw 20-25 people laying on the ground -- many of them dead or very badly injured. He said he saw no police when he first got outside.
Although Pearce said he did not hear the gunmen say anything, a different witness told Radio France that the attackers entered the hall firing rifles and shouting "Allahu Akbar."
"It was a scene from hell," the witness said. "The concert stopped and everybody lay on the ground and they continued to shoot at people."
On the Facebook page of the band that was performing, Eagles of Death Metal
, a post said it's unclear where the band and crew are and how they're doing.
But Michael Dorio, the brother of the band's drummer, told CNN his brother is OK and that he spoke with him after the attack.
"He had been performing and heard the gunshots," Dorio said. "The whole band heard the gunshots before they saw anything and stopped playing, hit the deck and kind of went backstage and exited as fast as they could."
When he first spoke with CNN, Pearce said he still had friends inside the Bataclan. He was communicating with them by text message; they were hiding.
"This is terrible," he said, his voice cracking. "It was horrible."
Security at the scene
Security at the concert was fairly lax, according to Pearce. There weren't metal detectors, he wasn't patted down, and the security guards didn't look in his bag. They just looked at his ticket.
"Security was very poor," he said.
'It felt like 9/11 all over again'
CNN iReporter Chris Morrow from San Diego was staying just a ten minute walk from Bataclan and five minutes from the Cambodian restaurant on Rue Bichat were 14 people were killed.
She was covering the AirBnB Open, an AirBnB event. "I was editing and putting stuff up on CNN when I heard an explosion and pop, pop, pop, which sounded like gunfire. I was also hearing a lot of sirens," she said.
"I tweeted, 'is this normal' and I had people calling me saying 'stay indoors, there's been an attack.' I then looked out of my window, the lights were out but I saw four men carrying guns by the restaurant area. I couldn't make anything out because all the lights were out. I instinctively grabbed my phone and started filming out of the window."
"The men were huddling around and there was no one on the street except them. They had long shotguns and seemed hysterical, screaming and not really sure what to do. They tried a few apartment doors, trying to get in but they were locked. In the end, they ran towards the river. I am not sure if they were police or the attackers."
"I feel petrified but Twitter has been great and made me feel like I'm not alone. Being American, I feel out of my element. It felt like 9/11 all over again. I had a feeling of fear and being paralyzed like when I turned on the TV and watched a plane flying into the tower."