MIAMI — Two F.B.I. agents were killed and three others injured as they were serving a warrant in South Florida on Tuesday morning in one of the deadliest shootings in the bureau’s history.
The F.B.I. said the incident occurred just after 6 a.m. as the agents descended on an apartment complex in the city of Sunrise, which is west of Fort Lauderdale. The agents were serving a warrant related to a case involving violent crimes against children.
Officials said the man being investigated, whose identity was not released, had apparently barricaded himself inside the complex and was found dead. A law enforcement official said it appeared that the man had killed himself before agents were able to arrest him.
Christopher A. Wray, the F.B.I. director, identified two of the agents killed as Special Agents Daniel Alfin and Laura Schwartzenberger.
“Every day, F.B.I. special agents put themselves in harm’s way to keep the American people safe,” Mr. Wray said in a statement. “Special Agent Alfin and Special Agent Schwartzenberger exemplified heroism today in defense of their country. The F.B.I. will always honor their ultimate sacrifice and will be forever grateful for their bravery.”
Ms. Schwartzenberger, 43, who had been with the F.B.I. since 2005, was part of the violent crimes against children squad in the bureau’s Miami field office, court records show. She was assigned to the Innocent Images National Initiative, a part of the F.B.I’s cyber crimes program established to combat the proliferation of images of child sexual abuse online.
Mr. Alfin, 36, who had been a special agent since 2009, was assigned to the Miami Child Exploitation Task force. He discussed his role in an online F.B.I. article about the 2015 arrest of a Naples, Fla., man, who ran what the bureau described as the world’s largest child pornography website called Playpen, which had more than 150,000 users around the world.
“We mourn the tragic loss of two of our F.B.I. colleagues who were killed today in the line of duty,” the acting U.S. Attorney General, Monty Wilkinson, said in a statement.
Gov. Ron DeSantis of Florida also offered condolences.
The F.B.I. squads that work crimes against children are considered some of the most difficult assignments because of the disturbing and graphic nature of the cases they handle. Agents typically review horrendous depictions of children being sexually exploited, images that are then shared with others online.
Two of the wounded agents were transported to the hospital, the F.B.I. said. The third did not require hospitalization.
There was a heavy police presence around the Water Terrace apartment complex on Reflections Boulevard, in a residential neighborhood in Sunrise. The police asked commuters to avoid the area and residents to stay home. Officers from various police agencies swarmed the neighborhood.
The police set up a perimeter about half a mile north, restricting access to the complex and surrounding areas. Officers cordoned off a large swath of Nob Hill Road and set up a staging site in a nearby rehabilitation hospital.
Officers stood in a somber line saluting as a gurney carrying one of the bodies draped in an American flag was placed into a fire rescue truck at the Broward Health Medical Center in Fort Lauderdale. A procession of dark law enforcement S.U.V.s and motorcycles with sirens and lights then escorted the ambulance to the county medical examiner’s office.
The agents shot on Tuesday were the first who had been fatally shot in the line of duty since November 2008, when Special Agent Samuel S. Hicks, 33, was killed while also serving a search warrant, according to the F.B.I.
Mr. Hicks was part of a team of agents executing an arrest warrant at a house near Pittsburgh that was connected to a drug trafficking ring, the bureau said.
The shooting on Tuesday was one of the worst in the history of the F.B.I.
In 1986, two agents were killed in Miami and five others wounded during the pursuit of two violent bank robbers who were also killed in the exchange. The gun battle at the Suniland Shopping Plaza in what is now the village of Pinecrest was the deadliest in F.B.I. history.
In November 1994, two agents were killed, a third agent was wounded and a 15-year-old boy was shot in the leg when a man came into the cold case squad room of the Washington, D.C., Police Headquarters and opened fire with an assault rifle, according to the F.B.I.
A police detective was also killed during the shooting. The gunman, a suspect in a triple killing a month earlier, had left notes saying he planned to kill members of the local police homicide unit, the F.B.I. said.
Johnny Diaz reported from Miami, and Adam Goldman from Washington. Katie Benner and Seamus Hughes contributed reporting from Washington, Maria Cramer from Maplewood, N.J., Michael Majchrowicz from Sunrise, Fla., and Patricia Mazzei from Miami.