Why doesn't the elevator on the east wing work after 6pm?
Answer
The Help Desk in KL155 (The Lantern) closes at 6pm, so for security reasons the east wing elevator shuts down at that time. Check out books and other materials at the Services Desk on the 2nd floor and use the west wing elevator after 6 pm.
This is a bad reason. The student help desk is manned by a single student, not a security guard. The stairs are right there anyway, so any security threat is still totally unhindered after 6pm with or without the elevator.