Deputies with the Broward County Sheriff's Office are investigating reports of an active shooter at Marjory Stoneman Douglas High School in Parkland, Florida.
Officials with Margate Fire Rescue are preparing for a mass casualty incident.
The SWAT team is on scene investigating the incident. Police and deputies are surrounding the school with their guns drawn as they guide students outside of the school to safety.
The Broward Sheriff's Office says there are reports of victims. The extent of injuries remains unknown.
A student spoke to ABC News and told George Stephanopoulos "at least 3 people are dead outside my door." He said he was evacuated from the school with other students.
Broward Sheriff says the shooter remains on the loose, as of 3:22 p.m.
The Coral Springs Police is advising teachers and students at the school to remain barricaded inside until police reach them.
The FBI and ATF are responding to the scene.