A woman walking on the Upper East Side this evening was struck with such force by a garbage truck that her body was cut in half, authorities said.

The woman, whose identity is not yet known, was on 1st Avenue between 90th and 91st streets around 5:45 p.m. when the private sanitation truck slammed into her, sources said.

The woman was pronounced dead at the scene. Police are still investigating the accident but said the driver of the truck remained at the scene.