A 19-year-old American college athlete, found dead at the base of a 35-foot cliff in a dry moat in Bermuda on Monday, died from the fall, officials said Thursday.

The athlete, Mark Dombroski, was on the island for a rugby tournament that ended Saturday. It was a “tragic accident,” Sean Field-Lament, the Bermuda Police Service superintendent, said in a news conference on Thursday. “We may not ever find out how he came to fall.”

There was no evidence of foul play in a post-mortem examination, Dr. Christopher Milroy, who conducted the autopsy on Wednesday, said during the news conference.

Neither he nor Mr. Field-Lament was able to confirm how or why Mr. Dombroski, who was a freshman at St. Joseph’s University in Philadelphia, went over a cliff in Fort Prospect — a colonial-era fort in a park near a sports center where his team had played.