Thursday's brief hostage situation at the University of Louisville marked the first time the school used its campus alert system in a non-weather emergency.Since October, U of L has had a system of alerts that notify students of emergencies or closings, and until yesterday it has been used only for thosepurposes.There are nine levels of alerts on campus. The first few include phone calls, e-mails and text message alerts. The University was prepared to sound a less high-tech alert just before things calmed down.“We were just getting ready to activate the sirens when everything got the point that it stabilized and we didn’t need to go to that route," says U of L emergency manager Dennis Sullivan.The hostage situation, in which police say a woman pulled a gun in the university’s Health Services building, was quickly defused, but she was later charged with the deaths of her two children.Sullivan says after yesterday’s episode, about six hundred students and faculty members signed up to receive text message alerts.