MADISON, Wis. -

It is a communication system University of Wisconsin-Madison police hope they will never have to use in the event of an active shooter situation on campus. It is also a communication system they are confident may save lives if that situation occurs.

The WiscAlerts program has the ability to send out emails, texts and social media messages with one click of the mouse. UW has nearly 58,000 followers on Twitter, and being able to communicate quickly with the campus population is critical in emergency situations.

To receive text messages through the WiscAlerts system students, staff and faculty need to sign up through the university.

“Being able to reach people in a split second if there were to happen to be a shooting on campus or were there a major incident to let people know, ‘Hey, we want you to stay indoors or we want you to leave or whatever we want them to do.’ These modes of communications are instantaneous,” said Capt. Michael Newton with the UW Police Department.

When a gunman opened fire on the Purdue University campus killing 21-year-old Andrew Boldt of West Bend police on that campus began notifying students there to remain indoors. Purdue University has nearly 37,000 followers on Twitter.

Hundreds of people have gathered on Purdue University's campus for a vigil remembering Boldt.

Boldt was fatally shot Tuesday in the Electrical Engineering Building on the school's main campus in West Lafayette. Police have arrested another student, 23-year-old Cody Cousins, on a preliminary charge of murder.

Police say they believe Cousins targeted Boldt but are still trying to determine a motive for the shooting.

Purdue President Mitch Daniels was traveling Tuesday but offered his prayers for Boldt's family in a statement read at the vigil.

Provost Tim Sands says he hoped the vigil would be the start of a healing process for the university.

A teacher at a Milwaukee high school says she was devastated to learn that Boldt, her former student, had been shot and killed.

Boldt's high school calculus teacher remembers him as a brilliant mathematician who was a role model to his classmates.

Jean Morrell said Boldt was a high-level thinker who was so impassioned about his work that he often stayed after class to talk about math and robotics.

She said he was a "phenomenal young man" with a great mind and an equally great heart. She says she's sad he won't get an opportunity to make his contribution to the world.

The president of a Milwaukee high school said Boldt's mother is in shock over her son's shooting death.

The Rev. Warren Sazama of Marquette University High School said the family was having trouble comprehending Boldt's slaying Tuesday. He said Boldt's mother told him a person doesn't just wake up in the morning expecting her son to be the victim of a one-in-a-million tragic shooting.

Sazama said Boldt's mother was especially concerned about whether her youngest son, a senior at the same high school, could cope. Sazama said the Jesuit school will offer whatever prayerful support it can.