NEW YORK (1010 WINS) -- A pedestrian flagged down officials Monday afternoon to warn them of a gathering happening inside of a commercial building in the Flatiron District.

Police learned of the invitation-only event hosted by the Instagram account "ganjapigs" occurring on the third floor at 20 W. 23rd Street.

Once inside, NYPD discovered 40 people gathered, two of which managed to flee.

Authorities recovered a bag of marijuana, edibles, THC, and other paraphernalia.

The party was taking place at 4:20 p.m., on 4/20, a day that celebrates pot, officials said.

NYPD

​Officials issued trespassing summonses to 33 men and five women.

Five of the 38 received an additional summons for unlawful possession of marijuana

Two people brought in by police had outstanding warrants, officials said.

Another person had an "icard" in relation to a prior investigation regarding a Brooklyn burglary.