A woman injured at least three people and died of a self-inflicted gunshot wound after a shooting at YouTube's headquarters in San Bruno, California on Monday. Last December, a shooting at a California law office left two dead. That same month, a gunman killed two, plus himself, in a Houston workplace shooting.
While office shootings are rare, they are increasing. According to a 2018 report from the Bureau of Labor Statistics, workplace shootings went up by 83 cases to 394 total from 2015 to 2016 and they comprised 79 percent of all workplace homicides in 2016.
In light of this, criminal response experts are urging employers and employees alike to prepare for the worst.
"It's helpful to recap sort of the three best practices in an incident like this," says Chad Sweet, a former Department of Homeland Security chief of staff. "The three things that we emphasize over and over is either get out, hide out or, if necessary, take the shooter out."
The DHS defines an active shooter as an individual who is "actively engaged in killing or attempting to kill people in a confined and populated area." According to the agency, these shooting situations quickly evolve and are highly unpredictable, so it's vital that you determine the best and most reasonable way to protect your life.
Most businesses have a security team that runs active shooting drills and alerts employees about unsafe situations. Although there is no set number on how often these drills should take place, they should occur as often as fire drills, says Diego Redondo, former FBI special agent and director of public safety and risk management at John Jay College of Criminal Justice. You may want to ask your HR leader if the company has a plan in place.
When you receive an alert about an active shooter on company premises, Redondo tells CNBC Make It that your first thought should be, "I need to get out of here."
Here are three steps you should take if there's an active shooter in your workplace: