CHICAGO (CBS) — For the third time in two weeks, a person has been robbed on Northwestern University’s downtown campus.

Northwestern Police said the latest attack happened inside the Huron Superior parking garage at Northwestern Memorial Hospital.

A woman entered the elevator around 5:30 p.m. Tuesday, and saw two other people inside. One of them grabbed her cell phone when she tried to hop off on the 8th floor.

The victim resisted, and one of the suspects pushed her down. She injured her knee, but was expected to be okay.

Two days earlier, a 22-year-old Northwestern Law School student told police five people beat him with closed fists, and stole his laptop and cell phone near Fairbanks and Superior, near Feinberg School of Medicine.

Two weeks ago, a female faculty member was attacked on the third floor of the Erie Street parking garage. Three people pushed her to the ground, and stole her cell phone.