Aid groups are mobilizing relief efforts to help victims of the storm. Here, Candice Lopez, left, and Stephanie Davis help clean debris from Thelma Cox's mobile home near Shawnee, Okla., after it was destroyed Monday.
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Oklahoma City Bombing: The Albert P. Murrah Federal Building shows the devastation caused by a fuel and fertilizer truck bomb on April 19, 1995. The blast killed 168 people and injured more than 500.
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