The Runaway Skyscraperáá Murray Leinster

The first few paragraphs of Chapter 1:

The whole thing started when the clock on the Metropolitan Tower began to run backward. It was not a graceful proceeding. The hands had been moving onward in their customary deliberate fashion, slowly and thoughtfully, but suddenly the people in the offices near the clock's face heard an ominous creaking and groaning. There was a slight, hardly discernible shiver through the tower, and then something gave with a crash. The big hands on the clock began to move backward.

Immediately after the crash all the creaking and groaning ceased, and instead, the usual quiet again hung over everything. One or two of the occupants of the upper offices put their heads out into the halls, but the elevators were running as usual, the lights were burning, and all seemed calm and peaceful. The clerks and stenographers went back to their ledgers and typewriters, the business callers returned to the discussion of their errands, and the ordinary course of business was resumed.