Four people are dead and several others are injured after an “active shooter situation” sent a Georgia high school into lockdown Wednesday morning, according to authorities.

Nine people were taken to hospitals with injuries, according to the Georgia Bureau of Investigation. The bureau also said a suspect was alive and in custody.

Calls about an active shooting at Apalachee High School in Winder, Georgia, started coming in around 9:30 a.m., Barrow County Sheriff Jud Smith said.

“This is a very, very fluid investigation,” Smith said in a news conference, adding that officials would give more information at 4 p.m.