It was supposed to be a celebration for seniors to cap off their last year at Acalanes High School in Lafayette.
Instead, students spent hours in lockdown today after administrators say a student made threats against the senior class.
Dozens of parents waited outside the school anxiously for any updates, and some complained about the flow of information about their children. They said that police never came to talk to them, which made them even more nervous.
There was one thing they were pretty much all relying on -- their cell phones, and for one mom, one app in particular saved the day.
The suspect was eventually detained off of the school's campus, according to Lafayette police, but as parents and students waited for news, text messaging became a lifeline during the lockdown.
For Susan Candell, it wasn’t the text from her daughter that gave her peace. It was a text from the Lafayette Police Department saying that the suspect had been detained off campus.
“That made me feel a lot better,” she said.
Candell signed up six months ago for a “Nixle” alert, and says it was her saving grace today.
“I think it would have been better if the police came over and talked to parents,” Candell said. “It seemed like they had enough policemen.”
“They kinda wanted us to stay away -- not get in the way -- so it’s understandable,” said Cliff Wagener, another parent.
As police presence grew, so did the rumors, and the parents’ anxiety.
After roughly three hours, parents got the news from the superintendent.
Photographs by NBC Bay Area's Stephanie Cheung.