An Irish-American teenager died last Sunday after he plummeted to his death in what investigators have described as an accidental fall.

Thomas (Tommy) Gilliam, a first year University of Virginia (UVA) student, had just returned to his dorm after spending the day with his family. He later snuck onto the roof of the University’s physics building with a group of students and fell four stories.

Emergency services received a call shortly after 11pm on Sunday night and soon after they arrived at the scene of UVA physics building where they found the teenager. He was later pronounced dead at the UVA Medical Center.

"At this time, we do not believe that either foul play or alcohol were involved," said UVA spokesperson Carol Wood, "Nor do we believe that this was a suicide. Investigators believe it was a tragic accident."

The 19-year-old was enrolled in the College of Arts and Sciences and has aspirations of becoming a foreign policy major, according to his Facebook page.

Gilliam spent his early childhood in Charlottesville before moving to Dublin with his parents Vicki and father Tom, who work as missionaries.  He attended secondary school in Ireland and recently returned to the U.S. to start college.

The teenager had spent his final day with his family, attending church with his grandfather and then working on his resume with his dad.

"He said he had to finish a paper," says Tom Gilliam Jr, the young man's grandfather, told The Hook.

"He slipped and fell," says his grandfather.

UVA police issued a statement on the matter last Monday, saying that there had been an issue with one of the doors of the physics building.

"Unfortunately, with the snow and rain on Saturday and Sunday, the roof of the Physics Building was especially wet and slippery," says Lieutenant Melissa Fielding. "When Mr. Gilliam tried to walk along a part of the shingled roof, he was unable to keep his footing and fell 40 feet to the concrete below."

Fielding added, "We are aware that there is a group of University students who try to enter secured spaces on Grounds as part of a challenge. They do so illegally and at great risk to their personal safety."

A website called "The Bold and the Ruthless" details forbidden areas in the University, which included the physics building.

"As far as we know, [Gilliam] had no affiliation with our organization,"  Steve Norum, a fourth-year student with the Bold and the Ruthless told the “The Hook”, adding that the exploration of UVA's secured spaces was "very very common."

This is certainly a great tragedy," says Norum, advising, "Always remember safety; and ask, 'Could this potentially end badly?' If so, don't do it."

On Tuesday the medical examiner’s office concluded that Gilliam’s death has been officially ruled an accident.