They were still building the stage yesterday evening as the sun went down on Washington.
But today hundreds of thousands of students and their supporters will be there taking part in the March for Our Lives.
Their message for the politicians couldn't be clearer.
Most school massacres in the United States follow a depressing and predictable pattern.
First there is the horror and the shock. Then there are tears and teddy bears, and candles, and heartbreaking pain and sorrow.
And then the dead are forgotten by those who didn't know them or love them.
Until the next massacre tears another community apart.
But the slaughter of 17 students and teachers in Parkland, Florida, the other day seems to be different.
For this time there's a burning anger.
