The blaze was contained to the roof of the building, according to a Facebook post from the Greenwich Professional Firefighters.
Fire officials told Greenwich Time that the lightning strike occurred at about 1 a.m. and it smoldered for a while.
A fire alarm at 7:25 a.m. brought firefighters, who cut away a portion of the roof to extinguish the blaze, Greenwich Time said.
An unoccupied office on the third floor sustained water damage, Greenwich Time said.
Click here to read the story at the Greenwich Time website.
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