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The shocking deaths of two men in just four days who intentionally crashed the airplanes they were piloting highlights a form of suicide that's gaining more prominence.

On Monday, Duane Youd was killed after crashing a twin-engine Cessna 525 into the Utah home he owned just hours after being charged with domestic violence. Police said the 47-year-old intentionally piloted the aircraft into the building where his wife and a child were staying.

UT Duane Youd

Duane Youd was arrested on a domestic violence charge hours before he crashed a plane into his own home. (Utah County Sheriff's Office)

Photos of the wreckage showed the white plane charred and in pieces in the front yard nearby an overturned and crushed car. Most of the upscale house was still intact, but heavily burned in the front. Youd’s wife and the child escaped the crash unharmed.

Meanwhile, in Seattle, police are investigating the death of 29-year-old Richard Russell, an airplane mechanic, who stole a Horizon Air turboprop plane from Sea-Tac International Airport and crashed it on an island in Puget Sound on Friday night.

Officials said Russell was “suicidal” at the time of the incident. Investigators are trying to determine what happened -- including how Russell knew how to properly activate the buttons and switches needed to initiate takeoff.

These two incidents are part of six confirmed or suspected suicides by plane in the last four years.

Here is a list of other recent crashes involving possible or rumored pilot suicide:

- March 15, 2017 – 1 fatality

Xin Rong, an experienced pilot, took off from Ann Arbor, Michigan in a Cessna 172P and disappeared. The aircraft was found -- wrecked -- near Manitouwadge, Ontario, Canada with the right-hand door open and no human remains inside or nearby. Investigators believe that Rong deliberately jumped out somewhere en route and the aircraft ran out of fuel before crashing. His body has not been found and he was subsequently declared dead.

- Oct. 11, 2016 – 1 fatality

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In this Oct. 12, 2016 file photo, investigators look at the remains of a small plane along Main Street in East Hartford, Conn. (AP)

Jordanian student pilot Feras Freitekh was killed and his instructor injured after they reportedly argued and wrestled for control of the Piper PA-34 Seneca they were flying. The plane crashed into a utility pole near the Pratt & Whitney headquarters in East Hartford, Connecticut. Investigators concluded the crash was an intentional act motivated by suicide.

- March 24, 2015 – 150 fatalities

A Germanwings Airbus A320 crashed into a mountain while en route from Barcelona, Spain to Dusseldorf, Germany. Preliminary information indicates that the co-pilot, Andreas Lubitz, locked the captain out of the cockpit before deliberately crashing the aircraft, killing 150 people. Officials said Lubitz had previously been treated for depression and suicidal tendencies.

- March 8, 2014 – 239 fatalities

Malaysia Airlines Flight MH370 from Kuala Lumpur, Malaysia to Beijing, China disappeared after all contact was lost about 40 minutes after takeoff. It is assumed the aircraft crashed in the Indian Ocean and searches for wreckage have turned up empty. Experts have theorized that the pilot, Zaharie Ahmad Shah, selected a route that would effectively render the plane invisible on radar in order to commit suicide. The plane’s disappearance is still under investigation.

The Associated Press contributed to this report.