Two deadly gunbattles 40 years ago in southern Oklahoma between a pair of heavily armed prison escapees and Oklahoma Highway Patrol troopers still impact the way state police are trained and equipped today.

Then-Gov. David Boren called the events of May 26, 1978, in Caddo and Kenefic "the worst single tragedy in the 40-year history of this law enforcement agency."

Veteran troopers Billy G. Young, 50, Houston "Pappy" Summers, 62, and Lt. Pat Grimes, 36, were killed by two convicts who had escaped from the state penitentiary in McAlester on April 23. Another trooper, Lt. Hoyt Hughes, was wounded in the gunbattle. It all happened as most Oklahomans were preparing to celebrate the Memorial Day weekend.

The three would become the 14th, 15th and 16th members of the state police killed in the line of duty since the Department of Public Safety was formed in 1937, according to news reports at the time. The lawmen were killed trying to recapture escapees Claude Eugene Dennis and Michael Lancaster.