Florida shooting: 'There was blood everywhere' - student details moment heroic teacher returned after helping victims

The horror of a deadly mass shooting at a Florida high school this morning is becoming clearer as surviving students recount the ordeal. 

CNN reporter Sarah Ganim said a young freshman told her she saw the gunman walking down the hallway as he was breaking, or shooting out windows.

"She said, 'I just heard banging coming up the hallways, he got to the window, he shot out the window of the classroom. He just kept going'."

At that point the freshman started to hear people screaming. 

One of the teachers reportedly grabbed some jackets to try and go help with wounds, and when the teacher came back she was "covered in blood".

"There was blood everywhere and people needing help," she said.

The suspected gunman has been identified as 19-year-old Nicolas Cruz and has been taken into custody. 

Broward County Sheriff Scott Israel confirmed the number of fatalities stands at 17, and a number of injured people have been taken to hospital.