The lost back pack

As an every day I got up early, got ready myself, had a breakfast, and I took the road to La Guardia. I arrived to La Guardia at 7:45 AM, at the entrance I showed I.D.. And then a took the elevator straight to fourth floor. Then a went to my classroom, I left my back pack there and a went to the third floor next to the coffee bar. So I spent there like a half and hour studying. Then I went back to room 409. Couple classmates was there, but my back pack wasn't there. So I thought may be somebody hide it. I asked to all of them and nobody knew it. So I lost my back pack. Then after a while a teacher told me "why you don't go downstairs and ask to the security". So I went to the first floor to ask the security and he told me " I don't now anything, you have to take care it, but just in case leave me you phone number". Then a gave him my phone number and I went back to class. In the meantime the teacher has gone to get something I don't know where. So suddenly I saw through the door a security walking by. Then I went out and I told to the security about what happened and he told me "let me see what can I do for you", so a said OK. And I returned to the class. Haven't past not even five minutes the security was at the door with my lost back pack.