On the morning a fire forced the evacuation of her daughter’s school, Ruth Kobayashi found out about it when her smartphone bleated out the distinctive tone she knows she can’t ignore: the Orange County high school’s app-based emergency communications system.

The app, created by Newport Beach, Calif., startup Titan HST, sent her a series of reassuring messages: The fire was small and was quickly extinguished. Everyone was safe.

“It was great because kids don’t always have accurate information in an emergency,” Kobayashi said. “If I was just relying on my daughter to send me a text saying, ‘There’s a fire. They’re making us evacuate,’ you can imagine me thinking that the whole school’s burning down. I didn’t have to go through that.”

Since its release in 2016, Titan HST’s emergency communication system has been embraced by businesses, educators and the medical profession. One reason, customers say, is the system’s reliability.

Another? Americans are hungry for ways to feel safe and well-informed after active-shooter incidents and natural disasters of the past few years.

One-third of business owners are relying on advanced technologies such as apps, drones, wearable devices and building sensors to support workplace safety, according to Nationwide Insurance’s fourth-annual business-owner survey, conducted in June.

Vic Merjanian, chief executive of Titan HST, has been riding that wave since founding the company in 2013. In 2016, his company closed seed funding and began signing up clients.

Most recently, Merjanian said, Titan HST has signed a contract with the Cal State University system, beginning with the chancellor’s office. In April, the company signed a contract valued at $300 million with New York-based Titan Global, an unrelated security firm.

“People date from apps, you order food from apps,” Merjanian said. “You do everything from apps, right? So why can’t you get help from an app?”

Usage has exploded. Merjanian said the system was used 62 million times in 2017, up from 16 million in 2016. The private company doesn’t reveal revenue.