A woman who captured a video of the chilling moment gunfire erupted in the Orlando nightclub shooting is being remembered as a "genuinely good person," with a big heart and an open ear.

Amanda Alvear was at Pulse nightclub with friends when a gunman entered the premises and opened fire. Alvear was Snapchatting during the night, and happened to catch the terrifying moment shots started to go off in the club

The 25-year-old was later confirmed dead.

Mykol Marte was friends with Alvear. He said he discovered her Snapchat videos on Sunday morning, and filmed the clips, which typically would delete within 24 hours. He posted them to Facebook before it was known she had died.

He told CTV News Channel that seeing her in the video made him feel ill. "I'm still shocked and I still have that sickening feeling in my stomach," he said from Florida.

Marte said Alvear's family is still reeling from her death. "They're devastated; heartbroken to say the least," he said, noting that Alvear will be deeply missed.

"She was always happy. It didn't matter how bad her day was, if you came up to her with one of your problems, she would put her feelings aside just to try and console you and have an open ear," he said.

Police said 49 people died after gunman Omar Mateen entered Pulse nightclub and started shooting. Mateen later died in a gunfight with police.