Cause of death for autistic NYC boy Avonte Oquendo unknown

NEW YORK - The New York City medical examiner's office says the cause and manner of death for Avonte Aquendo, the 14-year-old autistic boy who disappeared from his school and was later found dead, cannot be determined, reports CBS New York.

Avonte disappeared from his Queens school on Oct. 4, setting off a massive search that included extensive searches of subway tunnels and regular announcements over the public-address system at subway stations.

His remains were found in the East River, seveal miles from where he vanished, in January.

Avonte had a form of autism that made him nonverbal.

The family's lawyer has filed a notice of claim, the first step in suing the city. Family members want an explanation from the city explaining how Avonte was able to walk out of school unnoticed.