As the grand, 850-year-old Notre Dame cathedral burns in Paris, the world is watching in sadness, including those of us in the Sister City of SF.

Images of the blaze, which began at 6:30 p.m. local time in Paris, began quickly circulating on television, YouTube, and social media, and this ancient symbol of the Catholic faith looks to be heavily destroyed โ€” though as of this writing the iconic front portion of the structure remains unmarred and intact. The cathedral's central spire, which was added in the 19th Century, has collapsed.

France's Interior Ministry has already made comments suggesting that firefighters may not be able to save the cathedral.

The Vatican has expressed its shock and sadness, and in chiming in on Twitter with his version of sympathy, President Trump suggested using flying water tankers to fight the blaze โ€” a suggestion French officials quickly brushed off saying it could collapse the entire structure of the landmark church.

Mayor London Breed expressed her sympathy in a tweet Monday afternoon, and the San Francisco Fire Department retweeted a message from International Association of Fire Fighters (IAFF):

Paris has officially been a Sister City of San Francisco since 1996.

As the New York Times reports, around 400 firefighters are battling the blaze, and one spokesperson said that the next hour and a half (after 9:30 p.m. local time) will be "decisive" in how much of the building can be spared.

The spokesperson said that the fire had begun in the cathedral's attic.

The cathedral was actively under renovation and partially surrounded by scaffolding prior to the fire. Just last week, 16 copper statues representing the Twelve Apostles and four evangelists were removed by crane in order to begin renovations on the delicate spire.