OKLAHOMA CITY - A remembrance ceremony on the 23rd anniversary of the bombing of the Murrah Federal Building made clear that no amount of time will ever completely erase the pain of the attack.

At 9:02 a.m. on April 19, 1995, a massive fertilizer and fuel bomb, built into the back of a rental truck, detonated in front of the federal building, killing 168 people, including 19 children. More than two decades later, the healing still continues.

"We come here to remember those who were killed, those who survived, and those changed forever," said Jennifer Walker, whose father, David Jack Walker, a HUD employee, was among those killed.

Walker read the OKC National Memorial and Museum's mission statement at the start of this morning's ceremony. "May all who leave here know the impact of violence, and may this memorial offer comfort, strength, peace, hope, and serenity."

Following the reading of the mission statement, Walker asked for 168 seconds of silence, one second for each victim.

The newly sworn-in mayor of Oklahoma City, David Holt, told those gathered on the cool, sunny morning that he is just as committed to fulfilling the Memorial's mission statement as his predecessors have been. But Holt pointed out that, while he was a sophomore in high school in 1995 and thus old enough to remember the bombing, the community's collective memory of the event is slowly fading.

"And it is incumbent upon my generation and rising generations," Mayor Holt stated, "especially if we live here in Oklahoma City, to carry on the lessons of April 19th."

Governor Mary Fallin, who was Lieutenant Governor at the time of the bombing, praised then-Governor Frank Keating for his handling of the tragedy and all that came with it.

"We had about 12,000 people that came from across Oklahoma, across the nation, and around the world, and participated in the relief and rescue efforts after the bombing," Gov. Fallin said, "and Governor Keating was a steady hand that inspired us all to step up at a time of crisis for our state."

Fallin says, for her part, she has learned that this remembrance ceremony is important for a number of reasons, but especially to let those most significantly impacted by the bombing know the state hasn't forgotten them.

"We will always be here, year after year to stand with them," Fallin said, "and to also honor and celebrate what became known as the Oklahoma standard."

The late Billy Graham, who spoke at the memorial prayer service four days after the bombing, was also celebrated.

Former Governor Keating noted that both Rev. Graham and his wife flew in and met with first responders, victims' family members, and survivors.

"Bill Graham stood with us in our darkest hour," said Keating.

A special musical tribute featured some of Graham's words from the April 23, 1995 service at the state fairgrounds arena:

"What an example Oklahoma City and the people of Oklahoma have given to the world," Graham said. "A tragedy like this could have torn this city apart, but instead it has united you, in a way you've never been united before."

"The spirit of this city and this nation will not be defeated," Graham concluded. Those words, which helped start the healing process, became part of the memorial itself, etched in stone next to the survivor tree.