WASHINGTON (AFP) - A gunman opened fire at a high school in southern Florida on Wednesday, killing at least 17 people.
Here are some of the deadliest mass shootings in the United States in the past three decades:
Vegas concert: 58 killed
A 64-year-old man whose father had been on the FBI's most wanted list in the late 1960s shoots down from his hotel room at a crowd attending an outdoor country music concert on Oct 1, 2017, killing 58 people and wounding 546 others before committing suicide. It is the worst mass shooting in modern US history.
Florida club: 49 killed
A heavily-armed gunman opens fire inside a gay nightclub in the city of Orlando on June 12, 2016, and kills 49 people. The attacker is killed in a shootout with police. He pledges allegiance to the Islamic State in Iraq and Syria (ISIS) militant group, which later claims responsibility.
Virginia Tech: 32 killed
A 23-year-old student of Korean descent goes on a rampage at Virginia Tech University in the town of Blacksburg in April 2007. He kills 27 students and five teachers before committing suicide.
Sandy Hook: 26 killed
A 20-year-old man kills his mother in Newtown, Connecticut, in December 2012 before blasting his way into Sandy Hook Elementary School and shooting dead 20 six- and seven-year old children and six adults. He commits suicide.
Texas church: 26 killed
A gunman shoots dead 26 worshippers during Sunday services and wounds at least 20 others at a Baptist church in the small rural community of Sutherland Springs outside San Antonio, Texas on Nov 5, 2017. Police say the shooter was found dead in his car.
Texas restaurant: 23 dead
In October 1991, a man shoots dead 22 people at a restaurant in the town of Killeen, Texas, and then kills himself. Another wounded victim dies later.
California office party: 14 dead
A radicalised Muslim couple storm a Christmas office party at a social services centre in San Bernardino in December 2015 and gun down 14 people, wounding 22 others. The couple are shot dead by police.
Fort Hood military base: 13 dead
In November 2009, a US army psychiatrist opens fire at his military base in Killeen, Texas, killing 13 people and wounding 42, before being overpowered by police.
New York immigrant centre: 13 dead
A Vietnamese immigrant shoots dead 13 people at a civic centre in Binghamton, New York, in April 2009, before killing himself.
Columbine High: 13 dead
Two teenage boys shoot and kill 12 classmates and a teacher at Columbine High School in Littleton, Colorado, in April 1999, before killing themselves.
Washington Navy Yard: 12 dead
A former serviceman shoots randomly at workers at the Washington Navy Yard headquarters in September 2013, killing 12 people before he is shot dead by officers.
Denver cinema: 12 dead
A young man wearing body armour storms a cinema showing a late-night premiere of a Batman film in Aurora, Colorado, in July 2012, opening fire and releasing tear gas. Twelve people are killed and 70 wounded. He is sentenced to life in prison.