On a quiet Tuesday in a small rural town an 18-year-old armed with an automatic rifle burst into a primary school in Texas and barricaded himself in a classroom full of nine and ten-year-olds.
By the time he was shot dead by police he had killed 19 children and two teachers.
It is the worst school shooting in the United States since 26 people were killed in Sandy Hook a decade ago.
And this massacre has, like 10 years ago, sparked calls for tighter gun controls.
Our Washington Correspondent Siobhan Kennedy is in Texas.