When a person working in a multi-story office with a basement (usually a skyscraper) chooses to use the basement bathroom for "number two" or "dropping bombs" instead of using the floor he or she works on.
Hence, to bomb the base.
A spin off the 90s DJ name "Bomb The Bass."
Derek: Hey, do you want me to drop off your mail?
Tom: Yeah sure. But the mail slot is in the basement. We are on the 18th floor. Why are you headed down there?
Derek: After that enchilada lunch I fear I have no choice but to bomb the base.