San Francisco was under an "excessive heat warning" on Friday, but that didn't stop employees at the Russian consulate from lighting up the fireplace, causing black smoke to billow from the red brick building in the Pacific Heights area of San Francisco on the eve of its closure.

The consulate was ordered by the Trump administration to be closed by Sept. 2 in retaliation for the expulsion of American diplomats from Moscow.

It's unclear what exactly was going on inside the building, but that didn't stop Twitter from speculating. Here are some of the best tweets about the smoky situation.

Jennifer Hayden of the Daily Kos tweeted, "A live look inside the Russian consulate in San Francisco, where smoke is reportedly billowing out of the chimney."

Perhaps consulate employees were simply baking some traditional Russian treats on their last day of work, another Twitter user proposed.

Washington Examiner commentary writer T. Becket Adams wondered:

NBC Nightly News' photo of a Russian consulate employee speaking to a San Francisco Fire Department firefighter was ripe for a caption contest:

One Twitter user pointed out that aside from the heat wave, the Bay Area was also under a "Spare the Air" alert due to poor air quality.

Others suggested they were burning more than just paper.