CINCINNATI — A cause of death hasn’t been determined for a 22-year-old college student who was detained for nearly a year and a half in North Korea before being sent home in a coma, an Ohio coroner’s office said Tuesday.

Hamilton County ’s Dr. Lakshmi Sammarco’s office released a statement saying Otto Warmbier’s family objected to an autopsy so only an external exam of his body was done. It said his medical records from an air ambulance service that brought him to Ohio and from the University of Cincinnati Medical Center, where he was hospitalized until his death Monday, have been reviewed, and the treating physicians have been interviewed extensively.

“No conclusions about the cause and manner of Mr. Warmbier’s death have been drawn at this time as there are additional medical records and imaging to review and people to interview,” the coroner’s office statement said, expressing “deepest sympathies” for his family and friends.

The funeral for Warmbier will be held at 9 a.m. Thursday at Wyoming High School, where he was an athlete and salutatorian of his 2013 class.

“All those that wish to join his family in celebrating his life are cordially invited,” said the Spring Grove Cemetery and Arboretum.

The coroner’s office daily report Tuesday included Warmbier in its listings with cause of death termed “pending.”

Wambier’s parents did not cite a specific cause of death but blamed “awful, torturous mistreatment” by North Korea. Doctors last week described Warmbier’s condition upon his return June 13 as a state of “unresponsive wakefulness” and said he suffered a “severe neurological injury” of unknown cause.

Warmbier, a University of Virginia student, was accused of trying to steal a propaganda banner while visiting with a tour group and was convicted of subversion.

He was sentenced in March 2016 to 15 years in prison with hard labor. His family said it was told he had been in a coma since soon after his sentencing.

President Donald Trump said Tuesday that Warmbier’s death after his lengthy detention in North Korea was a “total disgrace” and that if the college student had been returned home to the U.S. earlier, “I think the result would have been a lot different.”

Doctors said Warmbier suffered extensive loss of brain tissue and “profound weakness and contraction” of his muscles, arms and legs. Unresponsive wakefulness is a medical term for persistent vegetative state.

North Korea said Warmbier went into a coma after contracting botulism and taking a sleeping pill. Doctors in Cincinnati said they found no active sign of botulism or evidence of beatings.

Warmbier had planned to study in China in his third year of college and heard about Chinese travel companies offering trips to North Korea. He was leaving North Korea on Jan. 2, 2016, when he was detained at the airport.

Three Americans remain held in North Korea. The U.S. government accuses North Korea of using such detainees as political pawns. North Korea accuses Washington and South Korea of sending spies to overthrow its government.