An author and teacher was savagely beaten to death in her New York City apartment in a gruesome attack that left her lying in a pool of blood, and police arrested her son for her murder, sources said.

Karyn Kay, 63, had called 911 about 9:30am local time Tuesday trying to help her 19-year-old son, who was suffering from a seizure in her Midtown apartment, sources said.

But he suddenly turned on her and allegedly beat her to a bloody pulp, sources added.

Cops from Midtown North rushed to the scene and found her covered in blood lying face up on her kitchen floor with a fractured skull, broken eye socket and broken ribs.

The son also was covered in blood, the sources said, and he was arrested and charged with murder late Tuesday night.

Click here for more on this story from the New York Post.