Barbara Poma, owner of Pulse nightclub, where 49 people were killed, promised Monday that the club will "always continue to be the heartbeat of Orlando."
"I will not let hate win," said Poma, who said she started the gay nightclub 14 years ago to honor her brother, John, who died of AIDs in 1991.
"For nearly 14 years, Pulse has served as a place of love and acceptance for the LGBTQ community," she said. "It should be the last place for such a tragedy."
Vigils and memorials around the world
Poma told NBC News that she learned of the shootings Sunday from the club's manager in what she called "the most surreal phone call I'd ever received."
"And finally, it sunk in, and you can't wrap your brain around that, you just can't," Poma said.
"I can't stop — I can't stop imagining what that was like for them," she said after an emotional pause. "I don't think I'll ever stop that."