REVEALED: Arizona hot air balloon pilot at the helm during horror crash that killed four people had KETAMINE in his blood without legal prescription

The pilot of a hot air balloon that crashed in Arizona killing four people had ketamine in his system - even though he did not have a prescription for the drug.

Cornelius Petrus Jakobus van der Walt, 37, had levels in his blood above what would be considered impaired for driving, an autopsy found.

While ketamine is legal in Arizona with a prescription to treat mental health issues, the medical examiner said the South Africa native did not have one.

The report also recorded that rescue crews did not use the drug when trying to revive him. Van der Walt was piloting the balloon, which was carrying 13 adults, on January 14. Eight skydivers jumped before any issues.

Only the pilot and four others were on board when it went down in Eloy, 65 miles southeast of Phoenix.  Chayton Wiescholek, 28, and Atahan Kiliccote, 24, and Kaitlynn Bartrom, 28, were also killed in the crash.

Cornelius Petrus Jakobus van der Walt, 37, had ketamine levels in his blood above what would be considered impaired for driving, according to an autopsy

Aerial video shows firefighters arriving to battle the blaze, which left the ground completely charred

Footage shows a wall of flames at the site of the Arizona hot air balloon crash that killed four and left another person in critical condition at a local hospital

Valerie Stutterheim, a 23-year-old Scottsdale native, survived but was seriously injured.

A preliminary report cited an 'unspecified problem' as the reason for the crash.

'A review of multiple mobile phone videos revealed that the balloon was descending with a deflated envelope trailing from above,' said the report by the National Transportation Safety Board.

Horrifying footage showed the immediate aftermath of the crash, which also left one person seriously injured. 

A huge blaze ignited at the crash site, leaving a plume of dark smoke trailing into the sky.

Aerial footage showed firefighters arriving to snuff out the blaze, hosing down the blackened earth beneath their boots.

Chayton Wiescholek, 28, was on the aircraft with his girlfriend, Kinsey. She was one of the eight skydivers who jumped shortly before the crash

Atahan Kiliccote, 24, graduated from Carnegie Mellon University's College of Engineering in 2022

Eloy Police Chief Byron Gwaltney said the eight skydivers were able to 'exit the balloon without incident' to complete a 'planned skydiving event' shortly before the balloon went down.

He said the skydivers intended to land at the Eloy Municipal Airport, just down the road from the scene of the accident.

'The incident appeared to occur very quickly,' Gwaltney said. 'It's just an absolute tragedy for our community and for the people that we're working with today.'

Bartrom worked at the Fort Wayne Lutheran Hospital on the Advanced Cardiac Therapy floor and had recently graduated from nursing school.

Kiliccote, of Cupertino, California, attended Carnegie Mellon University's College of Engineering and graduated in 2022.

Wiescholek was from Union City, Michigan. His girlfriend Kinsey was one of the eight skydivers who jumped from the balloon shortly before the crash.

She was the last person to hear from him before his death.

'He texted her on the way down, saying, 'Goodbye, this isn't going to be good, I love you' and signed off,' Wiescholek's father told FOX 10.