Another lone gunman approached another campus full of students on Sept. 26, but this time there was no tragedy similar to the shootings at Virginia Tech University in April that killed 32 people and wounded many more.

Just 16 minutes after Omesh Hiraman, 22, walked on to the campus of St. John’s University, in Queens, New York, with a loaded rifle, students, faculty and staff received e-mail and text messages alerting them to the danger.

Campus police and an NYPD police cadet spotted Hiraman, wearing a hooded sweatshirt and a Halloween mask, almost immediately. Hiraman, a St. John’s student, was quickly arrested without a single shot being fired. But rumors spread that a second gunman was loose on the campus.

“From public safety. Male was found on campus with a rifle. Please stay in your buildings until further notice. He is in custody, but please wait until the all-clear,” Thomas Lawrence, St. John’s vice president for public safety, sent in a text message.

University officials said only 2,100 out of 20,000 students were signed up for the alert system. Lawrence’s text message, and two more that followed, were widely forwarded around the campus. By the end of the day, subscribers to the service had jumped to more than 6,500 students.

“I commend the administration of St. John’s University for effectively activating an innovative text-messaging system when a dangerous situation unfolded on campus,” New York Governor Eliot Spitzer said in a statement. “The alert system notified students and staff of impending danger in a timely and effective manner.”