“We knew that they were going to hear that more and more of their friends and neighbours had been in the explosion, and we knew they were going to go through the grief. So we decided to face this head on and work through the grief together,” said Ms Davis, whose school is a few miles from the city.

Soon after the federal building and its day-care centre was blown up, the President and his wife invited children to the White House, where they tried to comfort them as part of a nationally broadcast radio programme. On the radio, they urged children to write letters and express their feelings.

“There are many more good people in the world than those who are bad or evil,” Hillary Clinton told the six to 12-year-olds who were huddled on the floor of the Oval Office.

However, it was to their schools that many children brought their fears and confusion.

At Grover Cleveland elementary, pupils have been prompted to hold hands, talk about their feelings, write poetry and essays and paint posters thanking rescue workers. A six-year-old drew a picture of a ruined building collapsed on to sets of lifeless legs. Others depicted broken glass, fire, smoke and wreckage. Some even sent thank-you cards to the search dogs still sniffing for victims in the rubble.

“I feel very, very, very sad,” wrote one six-year-old in her journal. “Thank you for trying to find the cowards who did this,” wrote another in a letter to the incident’s investigators.