It was the deadliest act of domestic terrorism in the United States. The April 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City killed 168 people. Domestic terrorism is still a concern for law enforcement officials throughout the country.
At 9:02 AM, silence fell across the Oklahoma National Memorial and Museum grounds, once the site of the Alfred P. Murrah Federal building in Oklahoma City.
At that moment 15-years earlier U.S. Army veteran and right-wing militia extremist Timothy McVeigh delivered a highly explosive truck bomb to the site that claimed the lives of 168 people, including 19 children.
In a somber ceremony, family and friends read the names of those who lost their lives on that fateful morning.
In front of a crowd that included survivors of the attack, Department of Homeland Security Secretary Janet Napolitano paid tribute to victims of the deadliest act of domestic terrorism on U.S. soil.
"We honor the continued need for vigilance against the violent ideologies that led to this attack, so that we can recognize their signs in our communities and stand together to defeat them," said Janet Napolitano.
The 15th anniversary commemoration of the Oklahoma City bombing comes at a time when domestic terrorism is a growing concern in the United States.
Right-wing militia movements, like the one Timothy McVeigh belonged to, are on the rise. Nine members of the so-called Hutaree Militia in Michigan were arrested in late March, while allegedly planning an attack.
"These are people who are accused of trying to murder a cop in order to bring hundreds of law enforcement officials to the funeral, which they were going to attack with improvised explosive devices and missiles," said Mark Potok. "They were going to create their own little Armageddon."
Information Director Mark Potok, of the Southern Poverty Law Center that is based in Alabama, says hundreds of groups are on a watch list compiled annually by the SPLC.
"After 9/11, the attention of law enforcement in general turned overseas, and that seemed like a reasonable thing," he said. "But what we are looking at right now is a very resurgent movement. The militias and the larger anti-government patriot movement has really exploded in the just the last year or so. We count these groups, and we found a 244-percent increase in the number of groups in a single year, that is 363 new groups."
The latest rise of extremist movements in the United States occurs at a time when gun control laws are more lax, which concerns the Brady Campaign to Prevent Gun Violence Director of Federal Legislative Affairs Chad Ramsey.
"They have access to all sorts of dangerous weapons," said Chad Ramsey. "The assault weapon ban is gone. They can arm themselves to the teeth with AK 47's, AR-15's, Uzi's, 50 caliber BMG's, they can arm themselves with just about any type of dangerous weapon you can think of now.
Not all militia organizations promote violence or efforts to overthrow the government. And as Mark Potok points out, they have every right to form and express their views.
"These groups by and large operate perfectly legally under the Constitution," said potok. "It is not that they should all be thrown in prison for having what are very often strange ideas. But the point is out of the milieu of these groups come the occasional killers, the Timothy McVeighs, the Eric Rudolphs, the people who are really willing to go out there and blow up a building full of people."
Timothy McVeigh was executed in 2001 for his role in the 1995 Oklahoma City bombing, his co-conspirator Terry Nichols is serving a life sentence without parole in federal prison.