Three Chicago area siblings and students at Brown University returned home on Sunday night following this weekend's deadly mass shooting.

Two students were killed, and nine others were wounded in the shooting. On Sunday, authorities announced that the person of interest was released from custody, citing new information.   

They spoke with CBS News Chicago after landing at Midway Airport.

"At 4:07 p.m., there were people posting on this side chat saying, 'Why are people running out of Barus & Holley? There's something going on.' That's where the first warning of the shots were. Fifteen minutes later, we got the alert from the university," said Allison Cavallo.

"I heard the sirens and helicopters going over the school at one point. I checked my friends' locations, and I saw that they were there. I just got a little bit delayed, so I was going to go there. I was supposed to be there," said Natalie Cavallo.

"Two of my closest friends were planning to go together. My roommate was supposed to go. Brown is such a safe and loving place, no one expected this to happen," said Nicholas Cavallo.

Allison and Natalie are graduating next fall. Nicholas is set to graduate in 2029.

Their father, Alex, graduated from brown in 1994.