Officials at the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) were told by an informant that an attack was coming and that the Oklahoma City federal building was among the targets.

The source, Carol Howe, had impeccable credentials and had infiltrated a white supremacist compound which had ties to Timothy McVeigh, who carried out the deadly truck bombing, which killed 168 people and injured around 700.

But according to Blowback: The Untold Story of the FBI and the Oklahoma City Bombing, by journalist Margaret Roberts, the federal government ignored the intel, allowing McVeigh to carry out his evil plot.