On April 19, 1995, America was rocked by a homegrown terrorist attack — the Oklahoma City bombing. This Saturday, looks back at the heroes and the journalists who were there as the chaos unfolded. Tune in to “ON AIR LIVE: Oklahoma City bombing: 30 years later” at 9p/8C. Find out how to watch.

() On April 19, 1995, a former U.S. Army soldier parked a rented Ryder truck loaded with a powerful bomb made of fertilizer and fuel oil outside a federal office building in Oklahoma City.

The blast at the Alfred P. Murrah Federal Building killed 168 people, including 19 children, and injured more than 500 others in what remains the deadliest homegrown attack on American soil.

This Saturday marks the 30th anniversary of the bombing.

What happened on the day of the Oklahoma City bombing?

The explosion, similar to the terrorist car bombing that killed six people and injured 1,000 at New York’s World Trade Center in 1993, occurred just after 9 a.m., when most of the more than 500 federal employees were in their offices.

The blast could be felt 30 miles away. Black smoke streamed across the skyline, and glass, bricks and other debris were spread over a wide area. The north side of the building was gone. Cars were incinerated on the street.

Oklahoma City Bombing aftermath

The bombing notably accelerated movement toward a more guarded, more security-inclined America. It wasn’t long for the heart of Washington, D.C., to take on a bunker-like air.

A month after the attack in Oklahoma City, authorities set up concrete barriers and closed vehicular traffic to two blocks of Pennsylvania Avenue nearest the White House. The move was preemptive, intended to prevent destruction on a scale of the Oklahoma City bombing. The move was also ordered unilaterally, without notice or public debate. And it was permanent.

Elsewhere in the capital, the installation of barriers and steel gates lent a wary, distrustful look that is obvious today. Architecture critic Witold Rybczynski once observed: “We used to mock an earlier generation that peppered the U.S. capital with Civil War generals on horseback; now I wonder what future generations will make of our architectural legacy of crash-resistant walls and blast-proof glass.”

As the Washington Post noted years later, the Oklahoma City bombing effectively “ended the capital’s life as an open city. Suddenly, driving into a garage involved guards wielding mirrors to inspect car bottoms. Jersey barriers undid the designs of landscapers and architects. An architecture of fear came into vogue.”

Who are Timothy McVeigh and Terry Nichols?

The bombers were two former U.S. Army buddies, Timothy McVeigh and Terry Nichols. They shared a deep-seated hatred of the federal government fueled by the bloody raid on the Branch Davidian religious sect near Waco, Texas, and a standoff in the mountains of Ruby Ridge, Idaho, that killed a 14-year-old boy, his mother and a federal agent.

McVeigh timed the Oklahoma City attack to coincide with the second anniversary of the fiery end to the standoff in Waco, in which 76 Branch Davidians were killed.

McVeigh was convicted of murder and conspiracy on June 2, 1997. He was executed by lethal injection in June 2001.

Nichols was sentenced to life in prison.

The Associated Press and affiliate The Hill contributed to this report.