It was 12 years ago today that 168 people were killed in the bomb attack on the Oklahoma City Federal Building.
Timothy McVeigh, the war veteran who drove a bomb loaded truck to the building, was later convicted of murder and executed.
According to federal prosecutors, the attack was a twisted attempt to avenge the deaths of dozens two years earlier in the federal operation that ended a cult standoff in Waco, Texas.
Today, survivors of the Oklahoma bombing and families of those killed gather again at the site to remember.
This year's Oklahoma observance will also honor the 32 people murdered this week by a suicide-killer at Virginia Tech.