India, Sept. 2 -- A professor from Northwestern University went missing on Monday, prompting police to begin an urgent search. The 72-year-old Nina Kraus was last seen leaving her Ashland Avenue residence in Evanston, northern Chicago, Illinois, at 9 in the morning.

Mikey Perkins, Kraus' son, told the Evanston RoundTable, "She left home this morning on her own, didn't take her phone with her. Nine hours later, we're very concerned."

Kraus is thought to have been sporting long pants and a windbreaker when she left her house, as per a missing person poster released by Perkins.

According to the description provided, the professor has long silver hair, a "very fit" body, and is five feet four inches tall. She was last seen at the 1500 bloc...