Oklahoma City mourners marked the 12th anniversary of the bombing that killed 168 people.
Mourners gather each April 19 at the former site of the Alfred P. Murrah Federal Building to observe the anniversary of the bombing, which injured hundreds.
Participants observed 168 seconds of silence, followed by family members reading the names of their lost loved ones.
Organizers said attention is also focusing on the killings of 32 people at Virginia Tech by a student who then killed himself on Monday.
"Violence obviously is happening," said Nancy Coggins, spokeswoman for the Oklahoma City National Memorial & Museum. "We hope there are ways we can reach out to them and offer support. They will be in our minds and in our hearts."
Coggins said the "fairly low-key" anniversary observance will be "a little more prominent" this year because the crowd will hear from Republican presidential hopeful Rudy Giuliani, who was New York's mayor during the Sept. 11, 2001, terrorist attacks.
After the ceremony, Ron Norick, who was mayor of Oklahoma City in 1995, and Giuliani will discuss how they led their cities through acts of terrorism during a symposium at the museum.
In the federal building attack, a cargo truck packed with two tons of ammonium nitrate and fuel oil was detonated in front of the nine-story federal building on April 19, 1995.
Timothy McVeigh was apprehended less than two hours later. He was convicted of federal murder charges and was executed June 11, 2001. Terry Nichols, who met McVeigh in the Army, was convicted of federal and state bombing charges and is serving life prison sentences.
Another Army colleague, Michael Fortier, pleaded guilty to not telling authorities in advance about the bomb plot and agreed to testify against McVeigh and Nichols. Fortier was released from a federal prison in January 2006 after serving most of a 12-year sentence.
Prosecutors said the bombing was a twisted attempt to avenge the deaths of about 80 people in the government siege at the Branch Davidian compound in Waco, Texas, exactly two years earlier.