Story by Minyvonne Burke and Angela Dallman
The pilot in January's fatal hot air balloon crash in Eloy, Arizona, had elevated levels of ketamine in his system, according to a report released this week.
An autopsy report signed by the Pinal County chief medical examiner on Monday states that "ketamine was found in the cardiac blood" of Cornelius Van Der Walt.
The National Transportation Safety Board had said that an "unspecified problem" with the balloon’s "envelope," the bag that fills with hot air to make the balloon rise, may have led to the crash.
The NTSB said in a statement in January that investigators had not found any mechanical anomalies.
The Jan. 14 crash remains under investigation.
The hot air balloon, operated by Droplyne Hot Air Balloon Rides, took flight with 13 occupants. At around 5,000 feet, eight skydivers on the hot air balloon jumped out as planned, the report states.
"Immediately after the skydiving members of the party had jumped, the balloon was witnessed to partially deflate and begin to lose altitude, dropping to approximately 4,000 ft., where witnesses reported that the craft seemed to regain some control but continued to descend," according to the report.
When the hot air balloon was at about 2,000 feet, it was "witnessed to begin to free fall straight down at an unknown high rate of speed, eventually striking the ground." Witnesses called 911, the report says.
Van der Walt, 37, was taken to the hospital where he was pronounced dead. Three other people were killed. They were identified by police as Chayton Wiescholek, 28, of Union City, Michigan; Kaitlynn Bartom, 28, of Andrews, Indiana; and Atahan Kiliccote, 24, of Cupertino, California.
A fifth person was taken to the hospital in critical condition.
The report says that Van der Walt did not have a known prescription for ketamine and it wasn’t used in resuscitation efforts at the scene of the crash.
The Drug Enforcement Administration describes the drug as a "dissociative anesthetic that has some hallucinogenic effects." Ketamine is medically approved as an injectable, short-acting anesthetic and as a nasal spray for treatment-resistant depression, the administration says, but it can be abused.
Ketamine has a variety of effects on the body including hallucinations, distorting perceptions of sight and sound, and making the person feel disconnected from their body and environment, the DEA says.
The report did not state that Van der Walt had abused ketamine and did not say why he had it in his system. It lists his cause of death as multiple blunt force trauma and the manner as an accident.
Droplyne Hot Air Balloon Rides, which was founded by Van der Walt, did not immediately respond to a request for comment on Thursday.
The company temporarily halted services because of the crash, according to a message on its website.
This article was originally published on NBCNews.com
