She was hit in the head and then went into cardiac arrest when she reached Wyckoff Hospital.
More than a hundred of her friends and fellow officers gathered in the hospital chapel to pray for her.
The incident happened at Fresh Pond Road and Myrtle Avenue.
Witnesses say they first heard a crack, and then screaming. They saw the thick trunk breaking off, hitting the woman, who had been walking on the sidewalk with her sister. It struck her right in the head and trapped her under its weight.
Seconds later, Rypkema was bleeding profusely and the sister was screaming for help.
"It was like something out of a movie," witness Eli Kairey said. "I've never seen anything like that before."
Residents believe the branch fell due to vibrations from a passing train. Right near the tracks is a slope with trees neighbors say are rotting. Many say it was an accident waiting to happen.
"So when the train went by, it collapsed," witness Francisco Rodriguez said. "It broke into pieces when it fell."
A children's street fair on Myrtle Avenue had the block closed, meaning dozens of people saw the freak accident.
Some parents say they avoided the area near the tree, saying they were wary of the leaning tree before this happened.
"I'm a paranoid father, so I don't want anything to happen to my son," witness Scott Lopez said. "So I stay away from this area."
---
WEB PRODUCED BY: Bill King & Scott Curkin
----
Click here for more New York and Tri-State News