Americans are shocked and horrified by shootings like the one that took the lives of 27 at the Sandy Hook Elementary School in Newtown, Conn. on Friday.
But in a year with so many horrific shootings, does a gunman opening fire on unarmed people still surprise us?
"As a country, we have been through this too many times," said President Obama after the shooting. "Whether it is an elementary school in Newtown, or a shopping mall in Oregon, or a temple in Wisconsin, or a movie theater in Aurora, or a street corner in Chicago, these neighborhoods are our neighborhoods and these children are our children."
Here's a rundown of America's 10 deadliest gun massacres, before Sandy Hook.