My grief over Officer Collier's death has inevitably turned to anger. Anger at the cowards who ambushed and killed such a great and devoted member of the MIT community.Anger at myself. I find myself wishing that he was never on patrol that night but It gives me solace to know that he swore an oath to protect and serve, something which he truly believed in.The week of April 15th 2013 was the most surreal week which I have ever experienced. I never knew Sean personally but I have seen him around the area encompassing Buildings 56, 66, Stata and Koch. I am ashamed to admit that I was there on the night he died in Building 66 from 9:00pm to 10:30pm. I even smelled the gunfire but I mistook it for something else. Didn't even hear the quick, muffled, cowardly gunshots which silenced a great man. I left early that night (around 10:30pm) through the front of Building 66 that faces Ames St and E25. If I had simply turned around from Ames St. and and walked a little closer into the open courtyard between Buildings 66 and 68 maybe I would have seen his patrol car in disarray at the intersection of Stata, Koch and McGovern. Maybe I could have dialed 911 so he wouldn't have had to bleed out for several minutes. He died a hero's death and very quietly.But his selfless dedication to MIT, the city of Cambridge, and to his Country will echo throughout the ages I love you Sean. I wish I knew you personally. Somerville is proud of you. America is proud of you. And the World will remember you.