As reports of a gunman on the premises spread, students fled Platte Canyon High School in Bailey.
The small mountain town school was quickly evacuated.
Parents converged on the area, anxious for news.
Many students were clearly shocked that this could happen in their school.
Hundreds were moved away from the buildings in buses.
Police set up a cordon around the school and its neighbouring middle school.
There were numerous reunions just outside the police lines.
In many cases, the sense of fear and relief was palpable.
Police say they had to move in to save the hostages' lives.