Capt. Jim Mulligan of the Fort Myers Police Department and a witness discussed a shooting at Club Blu in Fort Myers, Fla., that left two teenagers dead.  FORT MYERS, Fla. — Two teenagers were killed and at least 18 people were wounded early Monday when attackers raked a crowd with gunfire outside a nightclub here that had been hosting a party for young people, the authorities said.  Witnesses said multiple gunmen opened fire at about 12:30 a.m. outside the nightclub, Club Blu, in a palm-tree-lined strip mall in this southwestern Florida city.  Officials refused to discuss a possible motive, but “this was not a terrorist act,” Dennis Eads, the interim Fort Myers police chief, said at an afternoon news conference. “We have three persons of interest in custody — I’m not going to go into who they are — and we are still looking for others.”  The club had advertised a beach-themed “swimsuit glow party,” meant primarily for teenagers, with live music, a $5 cover charge and no proof of age required. In a statement, the club’s owner said that the event had ended and that people were leaving when the shooting occurred.  Residents of the neighborhood around the club said the area had been troubled by drug dealing and violence.  A Facebook user calling herself Juss Olivia posted a video shortly after the shooting, saying she had been sitting in a car across the street, near her apartment, when she heard gunfire and saw about five people “spraying nonstop, running and shooting.” She and her friends said they had joined a crowd fleeing on foot and ducking behind cars.  The authorities identified the two victims who were killed as Sean Archilles, 14, and Stef’An Strawder, 18, both budding basketball stars who had just left the club.  Sean, a student at Royal Palm Exceptional School, was shot in the parking lot, and a girl with him was shot in a leg, said his brothers, John and Verly Francois. They stood outside their mother’s house, where family and friends had gathered to comfort her, and said it was hard to believe that an innocent outing with friends had ended in the death of their youngest brother.  “They were just walking to a friend’s house about a block away,” said John Francois, 19.  Sean, the youngest of four brothers, stood just 5-foot-6, but he was a basketball fanatic whose brothers called him “Baby Kevin Durant” because he looked so much like the N.B.A. star and always had a basketball in his hand.  “He really was like Kevin Durant; he could have been his son,” Mr. Francois said. “He loved to play basketball. He was always down for that. That, or chilling at home.”  Mr. Strawder, who went by the nickname Dee, was a star player at Lehigh Senior High School who would have been a senior in the fall and aspired to play college ball.  “My heart hurts, I’m furious, and I can’t stop shedding tears,” his cousin Napoleon Rayner wrote on Facebook.  Gov. Rick Scott, who traveled to Fort Myers to meet with local officials, said, “Not one of us can imagine losing a young person like this.”  The wounded ranged in age from 12 to 27, said Lisa Sgarlata, the chief administrative officer of Lee Memorial Hospital in Fort Myers. One person died at the scene, one was pronounced dead at the hospital, and Lee Memorial treated 16 survivors, Ms. Sgarlata said.  One of those still being treated, Timothy Settles, posted to Facebook a brief video of himself lying in a hospital bed early Monday, after writing, “I don’t wanna die.”  Jermaine Wilson, a witness to the aftermath of the shooting, said the parking lot had been filled with cars and loud music as the teenagers were departing the club.  “I saw everybody running,” said Mr. Wilson, 32. “A bunch of people were screaming names.”  Syreeta Gary said that her daughter, Anastasia, a 10th grader at Dunbar High School, had run from the scene holding hands with another girl but that they had been separated. Anastasia ducked between parked cars and curled up on the ground until the shooting stopped, the mother said.  “She said she felt the pressure of three bullets flying past her before she dove between the cars,’’ Ms. Gary, 35, said. “People were running everywhere.”  Fort Myers police officers and Lee County sheriff’s deputies arrived within minutes and started tending to the injured, Chief Eads said. “It was very chaotic,” he said. “It was still very active. No one really knew what was going on.”  That confusion was evident as the number of wounded climbed throughout the day. Some people took themselves to hospitals, unknown to emergency workers — some right away, some hours later. Joining Chief Eads and other officials at the news conference, the governor put the count at 18 injured and two dead.  Fort Myers, with about 68,000 residents, is a fast-growing city with big-city problems, including gang violence and a high rate of poverty. Its rates of homicide and overall violent crime, according to F.B.I. reports, are about triple the national average.  “We do have our own little knife-and-gun club that are responsible for anywhere from 8 to 15 percent of the traumas that we see,” said Dr. Drew Mikulaschek, a trauma surgeon at Lee Memorial. But he said he had never seen so many people hurt in a shooting.  A statement early Monday on the club’s Facebook page said: “We are deeply sorry for all involved. We tried to give the teens what we thought was a safe place to have a good time.”  It added, “It was not kids at the party that did this despicable act.”  It was at least the second time in 14 months that shootings were reported just outside Club Blu. In May 2015, two nonfatal shootings took place within 35 minutes directly outside the club, a state regulator’s investigative report said.  Club Blu cultivated an image that often veered from homespun to risqué. It advertises “New Orleans-style soul food” and $6.99 lunch specials, but other ads depict the club as a racy hot spot with blaring music and flowing liquor.  The club staged a “grand reopening” in May to debut what it described as an improved building. In a corner of an ad for the event, the club made a promise: “TIGHT SECURITY ALL NIGHT.” This year, however, the club’s liquor license was revoked.  The attack occurred just 43 days after a gunman killed 49 people and wounded more than 50 others at Pulse, a gay nightclub in Orlando, Fla. The attacker, Omar Mateen, who took hostages at the nightclub and was killed in a police shootout, had sworn allegiance to the Islamic State.  Follow Lizette Alvarez @LizetteNYT on Twitter.For the latest national news updates, follow @NYTNational on Twitter.  Lizette Alvarez reported from Fort Myers, and Richard Pérez-Peña from New York. Les Neuhaus contributed reporting from Fort Myers, Mike McPhate from New York, and Alan Blinder from Atlanta.  A version of this article appears in print on July 26, 2016, on page A17 of the New York edition with the headline: 2 Teenagers Killed in Florida Nightclub Shooting. Order Reprints| Today's Paper|Subscribe
Three people were detained for questioning. The police gave no immediate indication of a possible motive but said the attack was “not a terrorist act.”