The 13th Judicial District Attorney's Office will refile manslaughter charges against Thomas Brent Caldwell in light of a report recently released by the National Transportation Safety Board.

The 31-year-old Pryor man was piloting a Bellanca Viking aircraft in December of last year when the plane crashed in Drowning Creek near Zena. Caldwell survived the crash, but three passengers drowned as they were trapped beneath the plane.

The district attorney's office filed manslaughter charges against Caldwell for the deaths of Mariano Carlos Casas, 15, of Pryor; Eduardo Ortiz Robles, 20, and Campos Gonzalez, 33, both of Mexico.

In May, the charges were dropped against Caldwell after District Judge Robert Haney determined that there was no evidence that any criminal action was committed by Caldwell.

A report recently released by the NTSB stated that “the examination of the airplane revealed no pre-impact anomalies,” suggesting that nothing was structurally wrong with the plane to cause the engine to fail.

The report also listed “pilot error” as a contributing factor.

According to the accident report, the engine failed during flight. Caldwell extended the airplane's landing gear and performed an emergency landing in Grand Lake. Upon impact, the plane rolled and came to a rest upside down, partially submerged.

The report also states that, at the accident scene, authorities reportedly detected alcohol on Caldwell's breath and noted that his speech was slurred.

Authorities say five liquor bottles were found inside the plane - four had been opened.

Nearly six hours later, when Caldwell submitted to a blood-alcohol test, the results showed no alcohol in his system.

According to Federal Aviation Administration records, Caldwell purchased the plane nine months prior to the accident from a certified flight instructor. The previous owner said he had instructed Caldwell in the aircraft for approximately 10 hours, but Caldwell was not a licensed pilot.

Records also show that Caldwell refused to submit a completed Pilot Operator Aircraft Accident Report Form and his pilot logbook for examination. He told authorities he had not logged a flight in five months.