Worst mass shootings in U.S. history

Seventeen people were killed when a gunman opened fire inside a high school in Parkland, Florida, near Ft. Lauderdale.

Wednesday's shooting is one of the deadliest mass killing at a school in modern U.S. history, after the Virginia Tech mass shooting of 2007 and the Sandy Hook massacre of 2012.

Here's a look at some of the nation's deadliest mass shootings since 2012:

- Nov. 5, 2017: 27 people were killed when a gunman opened fire inside the First Baptist Church in Sutherland Springs, Texas, about 40 miles southeast of San Antonio.

- Oct. 1, 2017: Fifty-eight people were killed when a gunman opened fire on a crowd at the Route 91 Harvest music festival in Las Vegas from a room in the Mandalay Bay Resort and Casino.

- July 1, 2017: 28 people were hurt when someone opened fire in the Power Ultra Lounge nightclub in Little Rock, Arkansas. Police believe it may have been gang related.

- June 30, 2017: A 45-year-old doctor entered Bronx-Lebanon Hospital Center and opened fire killing one person and injuring six others before killing himself. He was a former employee of the hospital and believed his former co-workers were responsible for him losing his job.

- June 14, 2017: A UPS driver, who filed grievances about overtime work with the company, opened fire inside a San Francisco package facility, killing three people and injuring several others before killing himself.

- June 14, 2017: Six people were injured, including Rep. Steve Scalise, when a 66-year-old old man opened fire on a Republican practice for a charity baseball game. The gunman was killed in a shootout with police. The shooter was an outspoken opponent of President Donald Trump.

- Jan. 6, 2017: A 26-year-old man said he was working on behalf of ISIS when he opened fire in the baggage claim area of Fort Lauderdale-Hollywood International Airport. He killed five people and injured either others.

- June 11, 2016: A 29-year-old man entered a crowded gay nightclub in Orlando, Florida and opened fire killing 49 people and wounding 53 others with an assault-style rifle. SWAT officers responded to the shooting and killed the gunman, an American-born man who had pledged his allegiance to ISIS.

- Feb. 25, 2016: A 38-year-old man killed three people and wounded 14 others lawnmower factory where he worked in the central Kansas community of Hesston. The local police chief killed him during a shootout with 200 to 300 workers still in the building, authorities said.

- Feb. 20, 2016: A 45-year-old man is accused of randomly shooting and killing six people and severely wounding two others during a series of attacks over several hours in the Kalamazoo, Michigan, area. Authorities say he paused between shootings to make money as an Uber driver. He faces murder and attempted murder charges.

- Dec. 2, 2015: Two people opened fire at a social services center in San Bernardino, California, killing 14 people and wounding more than 20. They fled the scene but died hours later in a shootout with police.

- Oct. 1, 2015: A shooting at Umpqua Community College in Roseburg, Oregon, left 10 people dead and seven wounded. The shooter exchanged gunfire with police then killed himself.

- June 17, 2015: A 21-year-old gunman shot and killed nine African-American church members during a Bible study group inside the Emanuel African Methodist Episcopal Church in Charleston, South Carolina. Police contend the attack was racially motivated. He became the first person sentenced to death for federal hate crimes.

- May 23, 2014: A community college student killed six people and wounded 13 in shooting and stabbing attacks in the area near the University of California, Santa Barbara, campus. Authorities said he apparently shot himself to death after a gunbattle with deputies.

- Sept. 16, 2013: A mentally disturbed civilian contractor shot 12 people to death at the Washington Navy Yard before he was killed in a police shootout.

- July 26, 2013: A 42-year-old went on a shooting rampage at his Hialeah, Florida, apartment building, gunning down six people before officers fatally shot him.

- Dec. 14, 2012: In Newtown, Connecticut, an armed 20-year-old man entered Sandy Hook Elementary School and used a semi-automatic rifle to kill 26 people, including 20 first graders and six adult school staff members. He then killed himself.

- Sept. 27, 2012: In Minnesota's deadliest workplace rampage, a man who had just been fired pulled a gun and fatally shot six people, including the company's founder. He also wounded two others at Accent Signage Systems in Minneapolis before taking his own life.

- Aug. 5, 2012: In Oak Creek, Wisconsin, a 40-year-old gunman killed six worshippers at a Sikh Temple before killing himself.

- July 20, 2012: A 27-year-old gunman fatally shot 12 people and injured 70 in an Aurora, Colorado, movie theater. He was sentenced to life in prison without parole.

- April 2, 2012: Seven people were killed and three were wounded when a 43-year-old former student opened fire at Oikos University in Oakland, California. The shooter was charged with seven counts of murder and three counts of attempted murder, but psychiatric evaluations concluded he suffered from long-term paranoid schizophrenia and was unfit to stand trial.