Mina Justice was outside the Pulse Orlando nightclub on Sunday morning, trying to contact her 30-year-old son Eddie.
Police, FBI staff and medics were busily moving around the scene, where it has emerged that 50 people were killed and 53 were injured in the terrorist attack which is now being described as the worst mass shooting ever in the US.
Ms Justice was among the friends and relatives who had gathered outside venue, attempting to find out if their loved ones were ok.
Eddie had sent Ms Justice a text message when the shooting happened, asking her to call the police.
He told her he had ran into a bathroom with other club patrons to hide. He then texted her to say: “He’s coming.”
“The next text said: ‘He has us, and he’s in here with us,‘” she said. “That was the last conversation.”
Clubber Jon Alamo said he was at the back of one of Pulse's rooms when a man holding a weapon came into the front of the room.
“I heard 20, 40, 50 shots,” he said. “The music stopped.”
‘Last sip’
Rob Rick said the incident took place around 2am, just before closing time.
He said: “Everybody was drinking their last sip.”
He estimated more than 100 people were still inside when he heard shots, got on the ground and crawled towards a DJ booth.
A bouncer knocked down a partition between the club and an area in the back where only workers are allowed. People inside were able to escape through the back of the club.
Christopher Hansen said he was in the VIP lounge when he started hearing gunshots. The gunfire continued even after he emerged, when police were telling people to back away from the building.
He saw injured people being tended to across the street.
He said: “I was thinking, are you kidding me? So I just dropped down. I just said ‘please, please, please, I want to make it out’.
“And when I did, I saw people shot. I saw blood. You hope and pray you don’t get shot.”
On its Twitter feed, the Police Department asked residents to “stay away from area” and said that it was seeking support from local state and federal agencies. Later, employees in the area were asked to stay home if possible.
‘Keep running’
The club itself posted a message on its Facebook page about 3 am: “Everyone get out of pulse and keep running.”
Local police Chief John Mina said that, at 5am, the police decided to attempt a rescue, detonating two explosives to distract the gunman and to help clear the club.
“With that advantage,” the chief said, nine officers moved into the club to confront the gunman.
In the ensuing shootout, one of the officers was slightly wounded but saved by his Kevlar helmet, the authorities said.
“We rescued about 30 people,” Chief Mina said.
During the rescue and shootout, officers with the SWAT team - using an armored vehicle - entered the club and hurried people to safety. Many of them had sought shelter in other sections of the sprawling club.
AP