DENVER (AP/CBS4) – A Wyoming college student visiting Denver on spring break jumped to his death after eating a marijuana cookie that his friend legally purchased in one of Colorado’s recreational pot shops, authorities said Wednesday.

An autopsy report lists marijuana intoxication as a “significant contributing factor” in the death of 19-year-old Levy Thamba Pongi, a native of the Republic of Congo who fell from a motel balcony on March 11.

It marked the first time the Denver medical examiner’s office has listed a marijuana edible as a contributor to a death, said Michelle Weiss-Samaras, a spokeswoman for the office.

“We have not had that,” she said.

Investigators believe Pongi and his friends came to Colorado to try marijuana, Weiss-Samaras said.

The friends told investigators that Pongi ate the cookie and “exhibited hostile behavior” that included pulling things off walls and speaking erratically, the autopsy report said.

Attempts by the three friends to calm Pongi seemed to work until he went outside and jumped over the balcony railing, according to the report.

Denver police ruled the death an accident but said their investigation remains open.

Colorado law bans the sale of recreational marijuana products to people under 21. It is also illegal for those under 21 to possess marijuana, and adults can be charged with a felony for giving it to someone under the legal age.

Authorities said one of Pongi’s friends was old enough to buy the cookie from a pot shop. It was unclear whether the friend might face charges.

The medical examiner’s office had Pongi’s body tested for at least 250 different substances, including bath salts and synthetic marijuana, which are known to cause strange behavior. His blood tested positive only for THC, the psychoactive ingredient in marijuana, according to the report.

Dr. Scott Bentz said they see a number of patients every week who have seemingly overdosed on edible marijuana. They show symptoms from shortness of breath to paranoia.

“I think with edibles we’re in a bit of a danger zone,” said Bentz with Presbyterian/St. Luke’s Medical Center.

Bentz said it’s not typical of marijuana to affect impulse control. He adds that research is based mostly on marijuana that is inhaled, not ingested.

“The effects of the edible marijuana are not as predictable as inhaled marijuana,” said Bentz. “All of the old studies and text books and toxicology are based on the effects of inhaled marijuana or smoked marijuana.”

One of Pongi’s friends also tried the cookie but stopped after feeling sick, Weiss-Samaras said.

The marijuana concentration in Pongi’s blood was 7.2 nanograms of active THC per milliliter of blood. Colorado law says juries can assume someone is driving while impaired by marijuana if their blood contains more than 5 nanograms per milliliter of the chemical.

Officials at Northwest College in Powell, Wyo., say Pongi started taking classes as an exchange student in January. He was studying engineering.

“The Northwest College campus community continues to grieve after Levy’s death,” the college said in a statement. “All of us were deeply saddened by this tragic incident and feel for his family.”

– AP writer SADIE GURMAN contributed to this report

(TM and © Copyright 2014 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2012 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)