TUCSON, Arizona (CNN) http://www.cnn.com/2002/US/Southwest/10/28/university.shooting/index.html -- Four people were shot to death Monday at the University of Arizona College of Nursing, a police spokesman said. They included two female professors and the attacker, who may have shot himself, according to the university Web site. Police declined to provide details on the shootings, or to identify the fourth victim. They occurred about 8:40 a.m. (10:40 EST), a university spokeswoman said. The bodies were still in the building, which police were searching. A witness said a student angry over being barred from midterm exams entered a classroom and began shooting with a handgun. The witness said the gunman fired at one professor as a number of students ran out of the classroom where exams were being given. He said the gunman then fired at a second professor. The gunman, he said, then allowed the rest of the students in the room to leave. Another witness taking a test on the fourth floor of the Nursing College said she heard about 15 gunshots. It was "really scary," she said. "It was silent while he was shooting our teachers," she said. "I was afraid that I was going to get shot." After the shootings, the college and surrounding buildings were evacuated, university spokeswoman Lisa Wakefield. Other buildings closed besides the Nursing College were the College of Pharmacy, Life Sciences North and Basic Sciences, police said. The University Medical Center and other treatment facilities remained open. Police said people who fled the college after the shootings were gathering at a nearby alumni center, where counseling was available.