A gunman opened fire at a Connecticut elementary school Friday killing 26 people, most of them children. The tragedy is the sixth mass shooting in the United States this year, according to data from Mother Jones.
In the last 30 years, there have been 61 shootings across the country in which at least four people have been killed. Eleven of those incidents, according to Mother Jones, took place at schools.
Friday's shooting at Sandy Hook Elementary is the second deadliest school shooting in the country's history, after only Virginia Tech, in which 32 people were killed by a gunman in 2007, according to the Associated Press.
The Brady Campaign to Prevent Gun Violence provided The Huffington Post with data on where mass shootings have occurred in the U.S. since 2005.
Click on the interactive map below to see the location of the shootings, as well as more information about each of the incidents.