The Columbine High School massacre (sometimes simply known as the Columbine Incident) occurred on Tuesday, April 20, 1999, at Columbine High School

Columbine High School

Columbine High School or CHS is a high school in unincorporated Jefferson County, Colorado, United States.- History :Columbine High School opened in the fall of 1973. There was no senior class in its first year. The school's first graduating class was the class of 1975...

 in Columbine

Columbine, Colorado

Columbine is a census-designated place in Arapahoe and Jefferson Counties in the U.S. state of Colorado. Located mostly in Jefferson County, it lies immediately west of Littleton....

, an unincorporated area

Unincorporated area

In law, an unincorporated area is a region of land that is not a part of any municipality.To "incorporate" in this context means to form a municipal corporation, a city, town, or village with its own government. An unincorporated community is usually not subject to or taxed by a municipal government...

 of Jefferson County

Jefferson County, Colorado

Jefferson County , whose slogan is the "Gateway to the Rocky Mountains", is the fourth most populous of the 64 counties of the State of Colorado of the United States. Located along the Front Range of the Rocky Mountains, Jefferson County is adjacent to the west side of the state capital, Denver....

, Colorado, United States, near Denver

Denver, Colorado

The City and County of Denver is the capital and the most populous city of the U.S. state of Colorado. Denver is a consolidated city-county, located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains...

 and Littleton

Littleton, Colorado

Littleton is a Home Rule Municipality contained in Arapahoe, Douglas, and Jefferson counties in the U.S. state of Colorado. Littleton is a suburb of the Denver-Aurora Metropolitan Statistical Area. Littleton is the county seat of Arapahoe County and the 20th most populous city in the state of...

. Two senior students, Eric Harris and Dylan Klebold

Eric Harris and Dylan Klebold

Eric David Harris and Dylan Bennet Klebold were American high school seniors who committed the Columbine High School massacre. They killed 13 people—including teacher Dave Sanders—and injured 24 others, three of whom were injured as they escaped the attack...

, embarked on a massacre

Massacre

A massacre is an event with a heavy death toll.Massacre may also refer to:-Entertainment:*Massacre , a DC Comics villain*Massacre , a 1932 drama film starring Richard Barthelmess*Massacre, a 1956 Western starring Dane Clark...

, killing 12 students and 1 teacher. They also injured 21 other students directly, and three people were injured while attempting to escape. The pair then committed suicide

Suicide

Suicide is the act of intentionally causing one's own death. Suicide is often committed out of despair or attributed to some underlying mental disorder, such as depression, bipolar disorder, schizophrenia, alcoholism, or drug abuse...

.