Reports of a man falling into the Hudson River behind the Hedley building in Troy launched a search effort, Wednesday.

Several witnesses saw 38-year-old Ronald Marotta fall into the water while he was apparently working on the docks at  the Troy Marina -- but never saw him re-surface.

Troy police say the preliminary results from the autopsy conducted Thursday indicate that Marotta died from asphyxiation from drowning.

Troy Police say the investigation is now indicating that Marotta was on the seawall up over the dock at the time he fell, but say he suffered no head trauma. 

The autopsy results indicate he was unconsious at the time he fell.

Emergency crews were launched, including several boats with dive teams and a state police helicopter.