The president of Western Michigan University vowed school officials will review its policy for sending out campus-wide alerts after it failed to warn students about a gunman who killed six in apparently random shootings just miles from the university Saturday night.

In a letter addressed to the campus community Sunday, school President John Dunn announced a university-wide meeting Monday night to discuss concerns over the school's alert policy.

“Saturday's events occurred in three different county communities over a period of hours,” Dunn said in the letter. “It was 11:30 p.m. before our public safety officials were told the shootings were linked. ... Two of the three incidents happened miles from the campus, and while these incidents were not linked until very late in the timeline, we need to make adjustments in our own procedures to respond to extraordinary circumstances. Last night's incident clearly was one.”

Students and family members voiced frustration with the university on social media, arguing the school's lack of action could have jeopardized lives.

“I have family attending Western,” wrote Nicholas Alexzander in a Facebook post to the school. “Why were no warning emails sent out to your students? A shooter is killing (people) two miles from your campus. Why are you not warning your students? You guys dropped the ball! I thought this campus had more common sense than this.”

Others argued the school sent alerts for far more minor situations.

"I get like three phone calls and a text from Western Michigan University when there's a gas leak or something stupid on campus, but there's an active shooter around campus who has killed six people randomly and literally 80 percent of the student body is out and about because of the nice weather and a lot of them are decently drunk, and they don't even send out a... text message?" wrote Bruce Brown in a post tagged with the university.

petition on Change.org to have the school review its alert policies had garnered 1,400 signatures toward its 1,500 goal by early Monday morning.

On Saturday night, a single shooter killed four people parked outside a Cracker Barrel restaurant roughly six miles from Western Michigan University before opening fire and killing two people at Kia Seeyle of Kalamazoo, one and a half miles from campus. Earlier in the day, the same shooter injured a woman outside Meadows Townhomes, six miles from the school.

Police arrested Jason Brian Dalton, 45, of Kalamazoo, around 12:40 a.m. Sunday. Authorities called him a "strong suspect" in the shootings.

He remains behind bars at Kalamazoo County Jail Monday.