The Empire State Building and Christmas tree at the Rockefeller Center both went dark at 9 p.m. Tuesday night to honor the two slain NYPD officers.

Other buildings participating included the One World Trade Center, One Bryant Park and Chrysler building.

"Let us take these moments to reflect on our common values, and rededicate ourselves to moving this city forward together," Mayor Bill de Blasio said in a statement, according to WNBC-TV.

Images:

PHOTO: The top of the Empire State Building goes dark for the 2 fallen NYPD officers pic.twitter.com/Z62FZBBaNX

— Josiah Daniel Ryan (@JosiahRyan) December 24, 2014

The Empire State Building dims its lights to honour the two fallen NYPD officer pic.twitter.com/sw1a0fZYv0

— Steven D'Souza (@cbcsteve) December 24, 2014

VIDEO (@JosiahRyan): Empire State Building goes dark at 9 p.m. to honor slain NYPD officers http://t.co/Xch76P2xU5

— TheBlazeNOW (@TheBlazeNOW) December 24, 2014

Christmas tree at 30 Rock goes dark at 9 pm in honor of slain NYPD officers pic.twitter.com/8ygmInt72T

— Jon Passantino (@passantino) December 24, 2014

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