In the black of night, mysterious singaling

Last night around 00:30 I walked to a 24-hour store to buy some bedtime snacks. I passed a night security guard who always stands in the vicinity of one street corner. I said "hello" to him once, but got a stone cold face in response, not a flicker of acknowledgment.

Returning from the store, I passed his corner again. Just as I was about to cross the street, this man began striking something hard like an iron rod against a metal street pole: Clang! Clang! Clang! Clang! It was a terribly loud sound for this quiet hour.

I crossed the street and walked alongside a parking lot. In the parking lot beside me, the lights of three parked SUVs came on. Then: Clang! Clang! Clang! This time the clanging sound was coming from the direction in which I was headed.

Evidently, the clanging was a signal for something. I passed a man with frizzy hair talking on a mobile phone whom I sensed was involved, somehow. I half expected the SUVs to race out of the parking lot. This didn't happen. Three or four cars drove by, but they were driven normally and looked ordinary.

I looked at the man at the end of my block who was making the second clanging noise. He wore a uniform-jacket -- I couldn't make out the words printed on the back. He took off as I approached. He moved at a fast clip in the direction as I was headed.

After two blocks, this man crossed the street. He walked up to a street pole and went at it again: Clang! Clang! Clang! From across the street, I watched this. Then, turning to face a wall, he relieved himself.

What any of this was about, I have no idea.