(CNN) Norman Casiano crawled into a bathroom and wedged himself into a stall, crammed with at least a dozen people. They were hiding, crying and saying prayers under their breath.
Gunfire replaced the blaring music. Glass shattered.
“Please don’t let this be where I go,” Casiano prayed.
Casiano froze, certain the gunman was inches away. A figure loomed outside the stall door.
The shots sounded louder. They were getting closer. A man standing outside the stall collapsed in a pool of his own blood.
Casiano heard a laugh. The sound of “pure evil,” he said. “It didn’t sound like a person.”
The gunman, later identified as Omar Mateen, didn’t utter a word. There was another bloodcurdling laugh.
“It was like a laugh of satisfaction,” Casiano told CNN’s Anderson Cooper.
Mateen fired a round into the stall door.
“Please, please, please don’t shoot!” some victims pleaded.
“Please don’t do this. Let us go!”
Mateen aimed his pistol over the bathroom stall and opened fire. Casiano was hit twice and fell over. Many of those he was hiding with were dead.
Satisfied with the silence, the gunman left.
“One of the first things I hear when I close my eyes are guns, bullets hitting the floor and that laugh,” Casiano said.
He moved silently, spreading death
The first shots broke out around 2 a.m. It was almost closing time.
Some 300 or so people had crowded the club early Sunday morning. Many were dancing under flashing strobe lights. Shot boys served $5 skybombs.
Mateen entered the club from the back of the building, armed with an AR-15-type assault-style rifle and a Glock 9mm semiautomatic pistol.
He first headed to the most crowded part of the club, the main bar area. That’s where the massacre began.
The loud music blaring from the speakers and the darkness of the dance floor compounded the confusion.
Mateen carried out his killing spree, moving around like a man familiar with the club.
Chris Callen, a performer, said he’d seen Mateen at Pulse before. Mateen was “very friendly.” He seemed comfortable there. Callen estimated the killer regularly visited the club twice a month for about three years.
Hugs, laughter, last calls
Angel Colon said the night started as a great time. By 2 a.m., people were saying goodbye. There were hugs, laughter, last calls. Then the nightmare started.
“We just grabbed each other. We started running.”
Colon was shot several times in the leg. He went down and took two more shots. The gunman fired at a woman next to Colon.
“He’s shooting everyone that’s already dead on the floor, making sure… I’m thinking, I’m next, I’m dead,” he told reporters Tuesday.
Mateen aimed at Colon’s head, but the bullet struck his hand. Another bullet entered the side of his hip. People were stepping over him.
“It’s still fresh to me,” he said.
Others dove to the floor, crawling for cover. Some lunged for the doors, separating from friends, stepping over strangers.
Luis Burbano and his best friend ran to an employee access door. The shots were getting closer. He never looked back.
“That’d be the last thing I would see, the last memory I have.”
Ray Rivera, a DJ at the club, was playing on the patio. People were barreling out from the club.
A man and a woman dashed under his DJ booth to hide.
“The guy took off and the girl was down there panicking, and I told her she needed to be quiet and as soon as there was a break in the shots, I pushed her and said, “Let’s go.'”
Covering herself with bodies
Rivera and the woman bolted to safety, but others weren’t as fortunate.
For three harrowing hours, as the gunman took hostages, people crouched in a dressing room or in the air conditioning vents. One woman survived by covering herself with bodies in a bathroom.
Helpless, trapped, shocked and scared, they texted loved ones.
Eddie Jamoldroy Justice, a 30-year-old accountant, sought shelter in the bathroom. He texted his mom:
Mommy I love you
In the club they shooting
Trapp in the bathroom
Im gonna die
His mother, Mina Justice, tried to reassure him that she’d called 911 and help was coming:
Calling them now.
U still there?
Answer your phone.
Call them mommy
Im still in the bathroom
Im going to die
He then went silent. Justice was among the 49 who didn’t make it.
CNN’s Tom Foreman and Anderson Cooper contributed to this story.