A deaf Bronx man jumped to his death early Friday morning after he allegedly stabbed his girlfriend, leaving her in critical condition, according to police.

Neighbors say Michael Jones and his girlfriend of a few months, who is also deaf, fought yesterday, but the neighbors say they don't know why. They are in disbelief over what happened.

"I'm in shock right now. He's just such a cool person, he'd do anything for anyone. I can't believe this," says neighbor Alex Colon.

Neighbors say Jones had been acting different lately and was seen walking around late at night. However, because he was hearing impaired, no one knew what the problem was - not even his brother, who said Jones rarely gave up much information.

Inside the apartment building at 631 E. 168th St. police found blood stains by the elevator. Outside, neighbors made a makeshift memorial to Jones they say was a great guy.

Jones' brother says he didn't know about any problems in the couple's relationship. In fact, his brother told their mom that he wanted to marry his girlfriend.