Enrique Rios, 25, was one of fifty people to die in the mass shooting in an Orlando nightclub on Friday. View Full Caption Enrique Rios/Facebook

BEDFORD-STUYVESANT — A Brooklyn social worker on vacation in Orlando for a friend's birthday was among the 49 people slain Sunday in the worst mass shooting in U.S. history, according to family and reports.

Enrique Rios, 25, was mourned by relatives and friends who described their shock at discovering he was among those killed inside Pulse nightclub by gunman Omar Mateen, who reportedly pledged his allegiance to ISIS before the attack.

"Anyone who knew Enrique knew that Enrique was fun-loving," his mother, Gertrude Merced, 47, told reporters outside of a bodega at the corner of Ellery Street and Marcy Avenue Monday. "He was open, he was helpful. I miss my son."

Merced extended a plea for help on the crowd-funding site GoFundMe for donations to help bring her son’s body back home to Brooklyn.

“I come as a humble, hurt, devastated mother,” wrote Merced, who left for the airport around noon Monday to fly to Florida. “My family is torn apart and all I would like is to have my son with me so he can have the funeral he deserves.”

As word of the tragedy spread, Merced’s campaign quickly surpassed its $4,000 goal — attracting $19,603 as of 6:45 p.m. Monday — up from the $890 in funding that morning.

Rios' relatives mourned him as a caring person who looked after his friends and family — including his grandmother, with whom he lived, who suffered from Alzheimer's.

“He was always taking care of her,” said Adalgisa Colon, 56, the home health care attendant who helped Rios take care of his grandmother. Rios often cooked for his grandmother, helped her to bathe, and kept her cheerful, Colon said.

“He loved to laugh, make a lot of jokes,” Colon said in Spanish. "When I realized it was him, it shook me."

"Enrique was a special person," Rios' cousin Annette Elgazar told DNAinfo New York in a text message. "His heart was so beautiful."

Elgazar said the family urged others not to retaliate against Muslims in his name.

"Not all Muslims are bad. Stop the hate, stop the violence," Elgazar wrote, adding that there are "Muslims in our family and Enrique loved them."

Friends and other family members took to Facebook to mourn the loss.

Rios' friend Mario Dalmasi came to the Marcy Houses Monday afternoon to pay his respects to Rios' mother after he saw his friend's picture in the news.

"I saw the newspaper, I saw his face, I'm in shock," said Dalmasi. "My heart is crying right now."

Merced's neighbor Marisela Rodriguez, 50, described Rios as "a really good kid". She learned about his death on the news.

"When I saw his picture, I thought, 'Oh my God,'" Rodriguez said in Spanish. "It hurt us very much."

The last time Rios' neighbor, Diva Maria Colon, 51, saw him was after she had returned from a Florida vacation and before Rios left for his. Rios held the door for Colon and asked about her trip.

"I'm going there too," Rios told Colon. "I can't wait."

Police said Mateen, 29, opened fire inside Pulse — a gay nightclub in Orlando — just after 2 a.m. Sunday, killing 49 people before being killed by authorities.

Mateen used an AR-15-style assault rifle and a handgun, authorities told reporters in Florida.

New Yorkers gathered at the iconic Stonewall Inn in Greenwich Village and in Diversity Plaza on Sunday night to memorialize the attack. Mayor Bill de Blasio has planned to attend Monday night's vigil at Stonewall at 7 p.m.

Eric Perez, 48, Rios' stepfather's uncle, called Rios a "do-gooder" who was "always into something good." Perez said Rios was loved and accepted by his family.

"If a person in your family is a homosexual you should accept that person," said Perez. "You should love them for who they are."