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AGC History: Tragic 1955 Plane Crash Claimed Industry Leaders’ Lives

In 1955 the downing of a Denver-to-Seattle flight rocked the nation and AGC. All 44 passengers including four local AGC leaders died in a crash caused by one of the most notorious crimes of the era.

The AGC leaders were travelling home from Denver where they were attending a regional AGC conference. Click here for a clipping of a Nov. 3 1955 Daily Journal of Commerce article remembering the four leaders who had generously served the industry: Frank Brennan Elton Hickok James Purvis and Clarence Todd.

During his interview for a separate article John Frodesen (Farwest Construction) recalled the incident. Frodesen was at the Denver conference but was not on the ill-fated flight as he had decided to stay in Denver for a couple extra days.

The following is from a Wikipedia entry about the crash and the evil criminal who caused it:

United Airlines Flight 629 registration N37559 was a Douglas DC-6B aircraft named Mainliner Denver which was blown up with a dynamite bomb placed in the checked luggage. The explosion occurred over Longmont Colorado while the airplane was en route from Denver Colorado to Portland Oregon and Seattle Washington on November 1 1955. All 39 passengers and five crew members on board were killed in the explosion and crash.

Flight and Explosion

The flight took off at 6:52 p.m. Mountain time. Eleven minutes later Stapleton Airport tower controllers saw two bright lights suddenly appear in the sky north-northwest of the airport. Both lights were observed for 30 to 45 seconds and both fell to the ground at roughly the same speed. The controllers then saw a very bright flash originating at or near the ground intense enough to illuminate the base of the clouds above the source of the flash. Upon observing the mysterious lights the controllers quickly tried to determine if they were indications of an aircraft in distress and contacted all aircraft flying in the area; all flights were quickly accounted for except for United Flight 629.

Numerous telephone calls soon began coming in from farmers and other residents near the town of Longmont who reported loud explosions and fiery debris falling from the nighttime sky — the remains of Flight 629.


Investigators determined that the aircraft began to disintegrate near the empennage or tail and that the aft fuselage had been shattered by a force strong enough to cause extreme fragmentation of that part of the aircraft. The explosion had been so intense that investigators thought it unlikely to have been caused by any aircraft system or component. There was also a strong smell of explosives on items from the No. 4 baggage compartment.

Suspicions that a bomb had been placed in luggage loaded aboard the aircraft were fueled by the discovery of four pieces of an unusual grade of sheet metal each covered in a gray soot. Further testing of the luggage from No. 4 compartment showed that each piece was contaminated with chemicals known to be byproducts of a dynamite explosion.

The FBI certain that the aircraft had been brought down by a bomb performed background checks on the passengers. Many had purchased life insurance at the airport just before boarding. One such insuree was Daisie Eldora King 53 a Denver businesswoman who was en route to Alaska to visit her daughter. When agents identified her handbag they found a number of newspaper clippings containing information about Kings son John Gilbert Graham who had been arrested on a forgery charge in Denver in 1951. Graham who held a grudge against his mother as the result of an unhappy childhood was the beneficiary of both her insurance policies and her will. Agents also discovered that one of Mrs. Kings restaurants the Crown-A Drive-In in Denver had been badly damaged in an explosion; Graham had insured the restaurant and then collected on the insurance following the mysterious blast.

Agents subsequently searched Grahams house and automobile and found wire and other bomb-making parts identical to those found in the wreckage. They also found an additional $40000 in insurance policies; however Mrs. King had not signed either these policies or those purchased at the airport and they were therefore worthless. Graham told agents that his mother had packed her own suitcase but his wife Gloria revealed that Graham had wrapped a Christmas present for his mother on the morning of the day of Mrs. Kings ill-fated flight.

Faced with the mounting evidence and discrepancies in his story on November 13 1955 Graham finally confessed to having placed the bomb in his mothers suitcase telling the police:

I then wrapped about three or four feet of binding cord around the sack of dynamite to hold the dynamite sticks in place around the caps. The purpose of the two caps was in case one of the caps failed to function and ignite the dynamite … I placed the suitcase in the trunk of my car with another smaller suitcase…which my mother had packed to take with her on the trip.


Authorities were shocked to discover that there was no federal statute on the books at the time (1955) that made it a crime to blow up an airplane. Therefore on the day after Grahams confession the Colorado district attorney moved swiftly to prosecute Graham via the simplest possible route: premeditated murder committed against a single victim — his mother Mrs. King. Thus despite the number of victims killed on Flight 629 along with Mrs. King Graham was charged with only one count of first degree murder.

As the case progressed Graham quickly recanted his confession but at his 1956 trial his defense was unable to counter the massive amount of evidence presented by the prosecution. He was convicted of the murder of his mother and after a few short delays was executed in the Colorado State Penitentiary gas chamber on January 11 1957. Before his execution he said about the bombing as far as feeling remorse for these people I dont. I cant help it. Everybody pays their way and takes their chances. Thats just the way it goes.

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