A woman fell to her death from a swanky Midtown hotel Tuesday afternoon.

The unidentified woman plunged from the 18th floor of the 1 Hotel in Midtown at 2:45 p.m. while onlookers watched on from the crowded sidewalk below.

Witnesses say she had been up on the ledge talking to someone for some time and it seemed like she might return inside — but she eventually let go.

“It looked like she couldn’t hold on any longer,” said Isabella Rose Faro, 22

Police may have been in the process of negotiating with the woman as she was hanging from the ledge, sources said.

Police had ordered that airbags be set up at ground level but the woman fell before that could be done, officials said.