A student and a teacher were killed in a shooting at a middle school in Sparks, Nev., on Monday. A 13-year-old student told the Reno Gazette Journal the teacher was shot after the student pointed a gun at the teacher, and the teacher told the student to put it down. Here's a look back at major school shootings in U.S. history:
Dec. 14, 2012: Gunman Adam Lanza massacred 20 first-graders and six staff members at Sandy Hook Elementary School in Newtown, Conn. He shot his mother to death before going to the school, and killed himself as authorities arrived.
Feb. 27, 2012: T.J. Lane opened fire inside the cafeteria at Chardon High School in Chardon, Ohio, wounding five students. Three of those students later died. Lane was arrested a short distance away.
Feb. 14, 2008: A former Northern Illinois University graduate student walked onto the stage of a science lecture hall and opened fire, injuring at least 15 students. Six students were killed in the attack before the shooter took his own life.
April 19, 2007: Thirty-three people were killed in two separate shooting incidents at Virginia Tech University in Blacksburg, Va. The gunman killed himself after the second shooting, police said.
Oct. 2, 2006: A gunman took a group of girls hostage at West Nickel Mines School, a one-room Amish schoolhouse in Pennsylvania’s Lancaster County. He killed five girls, including two who died the next day. The shooter, Charles Carl Roberts IV, 32, killed himself.
Sept. 29, 2006: Christopher Williams, 27, went to Essex Elementary School in Essex, Vt., looking for his ex-girlfriend, a teacher. He couldn’t find her, but fatally shot one teacher and wounded another. Williams also killed his ex-girlfriend’s mother. He shot himself twice in the head after the rampage and was arrested.
Sept. 2, 2006: Douglas W. Pennington, 49, killed himself and his two sons, Logan P. Pennington, 26, and Benjamin M. Pennington, 24, during a visit to the campus of Shepherd University in Shepherdstown, W. Va.
Sept. 24, 2005: Jason McLaughlin, 15, shoots and kills classmates Seth Bartell, 15, and Aaron Rollins, 17, at Rocori High School in Cold Spring, Minn. McLaughlin was convicted and sentenced to prison. He will not be eligible for parole until he is more than 50 years old.
March 21, 2005: Sixteen-year-old Jeff Weise shot and killed five schoolmates, a teacher and an unarmed guard at Red Lake High School on the Red Lake Indian Reservation in Minnesota before taking his own life. Weise had earlier killed his grandfather and his grandfather’s companion.
Oct. 28, 2002: Failing University of Arizona Nursing College student and Gulf War veteran Robert Flores, 40, walked into an instructor’s office and fatally shot her. A few minutes later, he entered one of his nursing classrooms and killed two more of his instructors before fatally shooting himself.
Jan. 16, 2002: Appalachian School of Law graduate student Peter Odighizuwa, 42, who had recently been dismissed from the school, returned to campus and killed the dean, a professor and a student before being tackled by students. The attack also wounded three female students.
March 5, 2001: Charles Andy Williams, 15, killed two classmates and wounded 13 people during a shooting spree at Santana High School in Santee, Calif., about 10 miles northeast of San Diego. Williams was charged as an adult and sentenced to 50 years to life in prison.
Aug. 28, 2000: James Easton Kelly, 36, a University of Arkansas graduate student recently dropped from a doctoral program after a decade of study, and John Locke, 67, the English professor overseeing his coursework, are shot to death in an apparent murder-suicide.
April 20, 1999: Students Eric Harris, 18, and Dylan Klebold, 17, killed 12 students and a teacher and wounded 23 before killing themselves at Columbine High School in Littleton, Colo.
Aug. 15, 1998: Frederick Martin Davidson, 36, a graduate engineering student at San Diego State University, was defending his thesis before a faculty committee when he pulled out a handgun and killed three professors.
May 21, 1998: Two teenagers were killed and more than 20 people hurt when a teenage boy opened fire at Thurston High School in Springfield, Ore., after killing his parents. Kip Kinkel, 17, was sentenced to nearly 112 years in prison.
March 24, 1998: Two boys, ages 11 and 13, fired on Jonesboro Middle School in Jonesboro, Ark., from nearby woods, killing four girls and a teacher and wounding 10 others. Both boys were later convicted of murder.
Dec. 1, 1997: Three students were killed and five wounded at West Paducah High School in West Paducah, Ky. Michael Carneal, then 14, later pleaded guilty but mentally ill to murder and is serving life in prison.
Oct. 1, 1997: Sixteen-year-old Luke Woodham of Pearl, Miss., fatally shot two students and wounded two others at Pearl High School after stabbing his mother to death. He was sentenced the following year to tow life sentences.
Feb. 19, 1997: Evan Ramsey, 16, opened fire with a shotgun in a common area at Bethel High School in Bethel, Alaska, killing principal Ron Edwards and classmate Josh Palacious. Ramsey was charged as an adult and sentenced to 200 years in prison.
Feb. 2, 1996: Barry Loukaitis, 14, turns an assault rifle on his algebra class at Frontier Junior High School in Moses Lake, Wash., killing two classmates and a teacher. Loukaitis takes hostages for a short amount of time. He is later sentenced to two mandatory life terms without parole plus 205 years.
May 1, 1992: Eric Houston, 20, kills four people and wounds 10 at his former school, Lindhurst High School in Olivehurst, Calif. Prosecutors said the attack was in retribution for a failing grade. Houston was convicted and sentenced to death.
Nov. 1, 1991: Gang Lu, 28, a graduate student in physics from China, opened fire in two buildings on the University of Iowa campus. Five university employees were killed and two other people were wounded. The student fatally shot himself.
May 4, 1970: Four students were killed and nine wounded by National Guard troops called in to quell anti-war protests on the campus of Kent State University in Ohio.
Aug. 1, 1966: Charles Whitman pointed a rifle from the observation deck of the University of Texas at Austin’s Tower and began shooting in a homicidal rampage that went on for 96 minutes. Sixteen people were killed and 31 were wounded.