I did not want to believe what I had just heard.

I was in Professor Willits' class, it was very close to dismissal time.  Someone knocked on the classroom door, Miss Willits answered the door. The person said: "The President has been shot".  All the readers must understand that Professor Willits was an outstanding educator, very possibly the best I have ever had.   [She made the British Corn Laws of 1832 interesting]  She returned to her lecture and completed the class at the proper time.  We in the class just went on with her.
I thought that the interruption. was just that, a bit of a prank.  I had to rerun a chemistry experiment, so I crossed campus to the science building and did the experiment.  2 hours later I arrived at my room, the owner of the house had the TV on, and I learned of the news of the assassination