The Harry Potter author took to Twitter shortly after the shooting at gay nightclub Pulse following the discovery that Luis worked at Florida theme park Islands of Adventure's The Wizarding World of Harry Potter area, operating the Forbidden Journey ride.

"Luis Vielma worked on the Harry Potter ride at Universal. He was 22 years old. I can't stop crying. #Orlando," the 50-year-old wrote on Monday (13Jun16), referring to Islands of Adventure's parent company Universal Studios.

She then sent a wreath of red roses and carnations to a visitation held of Luis' family and friends on Friday (17Jun16), reported.

His friend Tim MCKenny posted a photo of the floral arrangement and note that Rowling sent on his Facebook page with the caption, "So... this happened."

The touching note read, "To Luis, who died for love. You will never be forgotten. J.K. Rowling".

Luis was a student studying to be a physical therapist assistant at Seminole State College of Florida, according to his Facebook page.

His family said that working at the Harry Potter ride was a dream come true.

"He loved being able to go and be part of that every day he worked," they wrote in his obituary. "There was no greater experience for him at this time."

Rowling spent time on Twitter reposting and replying to those who had met Luis at the theme park, including one man who said that the 22-year-old "brought smiles to everyone he met".

"I'm so, so sorry," she replied. "My heart goes out to you, all his friends and his poor family."

The author also paid tribute to another Harry Potter employee who was injured in the shooting, after she was made aware on Twitter.

"I worked with Luis he was a Gryffindor who would make you proud. We have a Slytherin who's still in the ICU. His name is Tony," Victoria Bidorini posted.

Rowling immediately responded, "I'm praying Tony pulls through. My thoughts are with all of you #LoveIsLove #Orlando".

In what has become the deadliest mass shooting in American history, 49 people were killed and more than 50 others were injured after gunman Omar Mateen opened fire at the gay nightclub. He was later shot dead by police.