Many people first learned about the shooting at Marjory Stoneman Douglas High School in Broward County from social media as students used their cell phones to alert their loved ones and post photos and video of the scene.

A "shots fired" text is the type of message no parent wants to receive from his or her children, but imagine the relief seeing a post with the captioning, "I'm safe."

Smartphones and social media gave students access to the outside world as they waited in lockdown for around an hour.

Snapchat, a popular app, was widely used. Some of the students posted to the app right as the shooting started.

Others updated as SWAT team members came in to evacuate.

Another student posted a picture from inside his locked down classroom to Twitter. He says he was able to check local news on his cell phone for updates.

Even the Broward County Public Schools was able to alert the public with this tweet.

The school district continued to update on where parents could pick up their kids and letting other parents know about grief counselors on campuses on Thursday.