13-page suicide note left by Cynthia Wachenheim who jumped 8 stories with baby in harness

The 10-month-old boy miraculously survived and was in critical but stable condition at a Harlem hospital Thursday, police said.

A New York police spokesman confirmed that the woman left behind a suicide note.

Bystanders were shocked when they saw the 45-year-old mother fall Wednesday afteoon.

Horrific scene: The 45-year-old woman's body was covered with a white sheet outside 102 Bradhurst Avenue after she leaped to her death with her son in her arms

Silver lining: The woman was pronounced dead at the scene in an apparent suicide, but her 10-month-old son is expected to survive

Evidence: Police found a seven-page suicide note inside the home written by the distraught mother saying that what she was about to do was 'evil'

Site of tragedy: The woman jumped to her death from her apartment in the upscale building at 147th Street and Bradhurst Avenue

“I wish I never witnessed that,” Steven Dominguez told CNN affiliate WPIX. “It’s disturbing, and horrible. The baby bounced off her chest onto the floor, face down and was crying. My mother tried to pick up the baby, but there was already a detective there.”

Earlier, neighbor said he heard yelling coming from the woman’s apartment before she fell.

The woman was arguing with a man, said Christian Johnson, a neighbor.

“I came home, they were arguing,” Johnson told WPIX. “I actually stopped to listen, and I heard screaming and the baby was crying. He just kept saying why wouldn’t you pick up the phone, why would you put that stress on me? Why wouldn’t you pick up the phone, why, why? He was screaming, ‘why, why’?”

Police did not release the name of the victim, but neighbors said she was a lawyer and was married.