Just before Morgan O’Sullivan opened FlyteCo Tower in northeast Denver in August 2022, he learned that the site of his new business was tied to a historic tragedy: the first proven bombing of a large commercial airliner in the U.S.

The three-story brewery, bar, restaurant and arcade is housed in the former Stapleton International Airport air traffic control tower. Marian Poeppelmeyer, the daughter of a pilot killed in the 1955 explosion, asked the FlyteCo Brewing co-founder if she could visit because “this is where the flight — her father’s last flight — took off from,” O’Sullivan said.

“We started to realize that the building that we occupied had a story of its own that far exceeded anything that we were doing here,” he added about the brand’s second location.

In honor of United Airlines Flight 629’s 44 victims as well as the first responders on the ground, a granite memorial will be installed next to the tower’s front entrance next year and unveiled to the public on Nov. 1 — the 70th anniversary of the attack. A symposium and a memorial dinner are planned for Oct. 31, and History Colorado will put up a display about the bombing next fall.

The mass murder occurred on the evening of Nov. 1, 1955, after the United flight took off from Stapleton bound for Portland, Ore.

Its 39 passengers and five crew members never reached their destination, as the plane exploded near Longmont.

John “Jack” Gilbert Graham — a Denverite on the radar of the county district attorney for forgery — had taken out a travel insurance policy before his mother, Daisie E. King, boarded Flight 629 on her way to Anchorage, Alaska, the Federal Bureau of Investigation reported.

“Shortly before her plane took off, Graham paused while escorting his mother to the gate at Stapleton Field, pushed six quarters into a vending machine and purchased $37,500 worth of insurance on his mother,” according to The Denver Post’s archives.

Graham, intent on collecting the insurance money, put a homemade time bomb in her luggage.

A 2005 Post story recounted: “Graham woke up from his nap at 4:30 p.m. on Nov. 1, 1955, and snapped open his mother’s large, tan Samsonite suitcase. He removed a bathrobe, a quilted lavender bag containing his own wedding pictures and two antique brass flasks. In their place, the 23-year-old left a ‘surprise Christmas gift’ for his mother. … It was a neat bundle of 25 sticks of dynamite, two blasting caps, a timer and an Eveready 6-volt battery.”

Graham eventually confessed to his crime and was put to death in a gas chamber in 1957.

The tragedy resulted in a federal law criminalizing the bombing of airlines and buses. As the first court trial to permit television coverage, it also set a new standard that has influenced news coverage of court proceedings.

The bombing occurred just four years after Colorado’s deadliest plane crash. On June 30, 1951, United Flight 610 was traveling from Salt Lake City to Denver when it hit a mountainside west of Fort Collins in Larimer County, according to the Aviation Safety Network. All 50 people on board died. Remains of the plane are still found on Crystal Mountain.

Control tower is a final remnant of airport’s past

Stapleton Airport — where Flight 629 departed and Flight 610 headed — was closed in 1995. The brand-new Denver International Airport took its place.

Denver’s Stapleton neighborhood took shape as the former airport property became the site of urban redevelopment. Named after former Denver mayor and Ku Klux Klan member Benjamin Stapleton, it was renamed in 2020 to Central Park after decades of pushback by residents from marginalized communities.

The control tower remains as one of the last glimpses into its past.

Now, the Denver Police Museum is among groups taking the lead on organizing and raising funds for a Flight 629 memorial. It has worked on the project for several years, president Michael Hesse said. The memorial will cost $6,000, and about $2,000 has been raised so far, Hesse said.

“There’s no memorial for these folks, in spite of the fact that it’s the second-worst mass (murder) event in the history of our state, with Sand Creek Massacre being No. 1,” Hesse said. “We didn’t think that was right.”

The museum’s volunteers found relatives of the Flight 629 victims and invited them to next year’s events.

In Weld County, where the plane crashed, the Flight 629 and Unsung Heroes Across America Committee, a separate nonprofit, is raising funds for another memorial — a meditation garden estimated to cost $1 million — with just $3,600 raised so far.

In the tragedy, “there (were), unfortunately, no survivors,” Hesse said. “The important thing was to provide justice.”

Pilot’s daughter seeks ‘full-circle moment’

Cynthia Owens was only 2 years old when Donald White, her father and the plane’s co-pilot, was killed in the bombing.

She doesn’t remember much of the day except what she heard from her late mother, who described White as a hard worker with a kind and caring disposition. He had been flying for about a decade and was saving money to buy the family’s first house when he died at age 26.

When Owens is with her brother and two stepbrothers, “we still talk about it all the time,” she said. So it surprises her to learn that many people aren’t aware of the bombing.

Because Owens hasn’t had much contact with her paternal relatives, “I’ve got lots of questions still,” she said. She’s hoping the memorial “will be a great full-circle moment” that gives her some answers.

Owens, who lives in Klamath Falls, Ore., also sees it as an opportunity to meet the families of other victims. And she wants to see the public and United representatives show up, too.

“When this memorial happens, I’d like to see people come out and take part in it and to honor these victims — because I really don’t think anything was done for them when it happened,” Owens said.

To travelers, she offers some perspective: “We all fly, and we all get kind of impatient and angry with the security lines,” Owens said.

“And I just have to tell myself, ‘Think back: If they would have had this when my father was killed, he might still be with us today.’ “