"You do not need to evacuate out of the building. I repeat. You do NOT need to evacuate out of the building..."

I was working late this evening. Around 7:15pm, someone used the broadcasting system of the building to tell us that there would be a test of the fire alarm. At the end of his notice, he said,

" You do not need to evacuate out of the building. I repeat. You do NOT need to evacuate out of the building. Thank you."

"Okay, no biggie," I thought and went on with my stuffs.

Ten minutes later, I knew I had been so wrong. The loud and sharp siren went on over and over and over again. The siren was accompanied by really blindingly bright flashes from many "emergency lights", one every 10 (or less) feet. It pounded on my eardrum and irritated my nerves. I started to develop a headache and wanted to scream. 20 min afterwards, a maintenance guy walked past our workplace.

"Excuse me", I said,"do you know when this will end?"
"After we walk through every floor to make sure it works", he replied with a smile.
"Oh... okay."
"Yeah."
"Er... Great..."
"It will be another 20 minutes."
"Ah, thanks!"
He smiled and walked away. Although I was not very pleased with the answer, I, at least, got some hope now.

Everything did end in another 20 min. (I mean, everything except for my headache...)