At 11:51, sergeants started to arrive. officers continue to arrive from the hallway and there is as many as 19 officers at that time in that hallway. reporter: officers did not enter the room until a janitor provided keys. they used keys from the y janitor because both doors were locked. they killed the suspect at that time. reporter: survivors inside both classrooms made desperate calls to 911. she identified herself, whispered she s in room 112. at 12:10 she called back advised ....