A doctor who killed his two young sons by throwing them over a hotel balcony and then jumped to his own death seemed to be hallucinating and sounded paranoid in a phone call two days earlier, his father said.

Oebele Van Dyk, 86, said he talked to his son the day before Edward Van Dyk flew to Miami to be with his wife and two sons, who were already staying at the Loews Hotel where the incident occurred. The boys were 4 and 8-years-old.

"He was very distraught. I think he was seeing things that didn't seem to be real," Van Dyk told The Miami Herald on Sunday in a telephone interview from his home in New York.

Van Dyk described his son as a "peaceful guy," who "never, never fought" and said his son did not have any history of mental problems.

He said he and his wife did not learn of the deaths until Sunday, when his daughter-in-law called him.

Edward Van Dyk was a radiation oncologist at Alton Memorial Hospital in Illinois.