At 8:35 p.m., everyone was onboard Continental Airlines flight number 11: 37 passengers and eight crew members. Not one of them had passed through a metal detector, and no carry-on luggage had been X-Rayed or inspected.
That's because it was May 22, 1962.
"I remember driving to the airport with my mother," said Melissa Ruck, a crash victim's daughter.
Ruck was just 8 years old on the spring day in Chicago in 1962 when she and her mother dropped off her dad at O'Hare for a business trip to Kansas City.
"He kissed my mother goodbye, and he turned around and said, 'I'll see ya later,'" Ruck said.
That was the last time Ruck saw her father, Rex Thomas, who had just turned 39 years old.
The Boeing 707 never made it to Kansas City. According to a report of the official investigation in 1962, the "aircraft disappeared from the (radar) scope" about a half hour into the flight.
Witnesses on the ground reported "loud and unusual noises" and "a big flash or ball of fire."
six minutes after the plane was lost on radar, it crashed in a farm field near Unionville, Missouri.
Ron Cook was 17 years old at the time and one of the first to find the wreckage.
"We walked up on the hill, and we could see the fuselage of the plane there and the wings," Cook said. "I guess you could just take an airplane and chop off the tail of it, and that's what it looked like."
"My mother just sat me down and said that my dad had died and was in heaven. That was all I knew for a long time," said Ruck.
However, there was more to the story. Initial newspaper reports suggested bad storms caused the crash, but airplane parts were scattered for 40 miles, the result of a "high-altitude breakup and disintegration in flight," according to federal investigators. They determined that an explosion had "originated in the waste towel bin underneath the washbasin counter of the right rear (bathroom.)"
FBI lab tests determined "the explosive used was dynamite."
"The last person they found was a flight attendant, and she was in a pasture just south of our house," said Ilajean Webber, a crash witness.
Also found on Webber's family farm was the body of passenger Thomas Doty, a depressed businessman with legal problems who had just purchased $300,000 in life insurance and six sticks of dynamite that authorities suspect he placed in the rear bathroom.
"[Do] you know how much that dynamite cost?" said local historian Duane Crawford.
Crawford says Doty bought the explosives for 29 cents per stick-- less than $2 to bring down a jetliner.
"This individual ripped that away, from all of us. You just live with this every single day. It's part of who you are and what you've grown up to be," said Ruck, who visited the crash site in Missouri Saturday for the first time.
In 48 years, there had never been a memorial marker, or even a ceremony, honoring the victims-- even though it was the first time a passenger jet had ever been sabotaged.
Saturday, a black granite wall was dedicated with the engraved names of the crew and all of the passengers killed in the crash, including Rex Thomas.
"We were your typical American family, and that all changed on May 22, 1962," Ruck said.
Some other things changed that day. The crash of Flight 11 ushered in a new genre of disaster books and films, including Arthur Hailey's Airport that was based on Doty's lavatory bombing.
Flight 11 ended the innocence of air travel. Today's passenger screening began after that incident.
"I am always willing to get scanned or have my luggage gone through. I know what can happen," said Ruck.
For the families of the 45 people killed that day, perhaps the most painful reminder of Continental Flight 11 was the flight number itself. For decades, Continental Airlines continued to use the designation Flight Number 11. It was never retired from use as has been the case in deadly crashes since then.
Finally, after being brought to the attention of airline executives, it was permanently retired last fall.
For more information, log on to the report of the official investigation on the explosion and crash and a Flight 11 chat room.
Additional information can also be found at the plane crash database.