Alexandrov, 71, father of four, had been an adjunct professor at the college since the fall of 2007. This semester, he was teaching Mathematics for Business to a class of about a half-dozen students in the School of Continuing and Professional Studies, an eight-week accelerated course in the lull of summer.
On Wednesday, Spigelmyer said, shortly before his scheduled 5:30 p.m. class, a staffer saw Alexandrov standing inside the rotunda railing. Security was called. Another staffer came out of her office and then ran for help.
Before long, three staffers and a school security guard gathered at the rotunda, Spigelmyer said. One of the staffers and the guard stood on either side of Alexandrov at the railing.
"They were talking to him," said Spigelmyer, "and trying to convince him not to do something drastic. He was not talking to them, to my understanding. There was not a two-way conversation. The next thing you know, he just dove off the ledge."
Witnesses screamed, causing students and staffers, including Alexandrov's wife, Olga, who teaches math at the college, to run to the rotunda, Spigelmyer said.
The Philadelphia Police Department is investigating the incident.
Memorial services are scheduled for 7 p.m. Tuesday, Aug. 9, at the Bryn Athyn Cathedral.
Students left messages on the college's Facebook page. One reads: "He was a remarkable professor. Everywhere you saw him, you saw Mrs. Alexandrov. Rest in peace."
"It is very distressing," Spigelmyer said. "Those at the college, the students, and the family, our hearts and prayers just go out to them."
Contact staff writer Kia Gregory at 215-854-2601, kgregory@phillynews.com, or twitter@kiagregory.