Amanda Alvear, 25, and Mercedez Flores posted on Snapchat from the nightclub before the shooting.
Alvear's friend Sandy Marte said one of Alvear's Snapchats showed a packed club full of revelers. Another, a selfie video of Alvear with a series of gunshots in the background.
Marte and Alvear bonded over breakups and health problems.
"She was loving, she was caring, she always had an open ear, she always wanted to help people," Marte said. "She had an amazing heart."
Marte said he understands what it's like to be at a nightclub during a shooting. He was at the Glitz Ultra Lounge in Orlando in February when two people were killed, and said he froze in place from the shock of it.