WEST LAFAYETTE, Ind. -- Purdue student Alex Foss died in an April 11 plane crash with THC in his blood, according to the National Transportation Safety Board's final report released last week.

The report indicated that 20-year-old Foss had two types of THC in his system, noting that the substance is the drug found in marijuana, according to the report, which did not indicate the levels of THC found in Foss's blood.

He also had caffeine and a byproduct of tobacco in his system.

Tippecanoe County Coroner Carrie Costello said their initial toxicology reports did not indicate THC in Foss's blood. However, the state's tests are not as comprehensive as the National Transportation Safety Board's, and Costello has resubmitted his samples for retesting.

Foss's death was ruled a suicide.

The evening of April 11, Foss wrote two suicide notes and went to the Purdue Airport. He checked out a Purdue Aviation Piper plane and climbed into the night sky at 7:40 p.m., according to the safety board's report. Purdue Aviation is a private company that operates at Purdue University's airport.

He made four traffic pattern landings at the Purdue Airport, then climbed into the darkness to about 4,000 feet heading northwest, according to the report.

About 10 miles from the airport, Foss made numerous turns, according to data collected from the wreckage. The data stops at 8:21 p.m. April 11 -- presumably the time of the crash, according to the report.

His plane crashed into a farm field between West Lafayette and Otterbein.

Foss died in the crash.

The plane wreckage and Foss were not found until the afternoon of April 12. Investigators did not find any mechanical malfunctions in the plane.

Reach Ron Wilkins at [email protected]. Follow on Twitter: @RonWilkins2.