NEW YORK - Investigators are considering sun glare as a possible factor in Tuesday's accident involving a group of kayakers and a ferry on the Hudson River.

Police say the New York Waterway ferry was leaving Pier 79 at 39th Street just before 6 p.m. when it struck 10 kayakers.

Five people were hurt, including one employee of the Manhattan Kayak Company who suffered a severe arm injury.  

"His bone was exposed," said NYPD Inspector David Driscoll. "He had lost a lot of blood and he was lapsing in and out of consciousness. He was rescued by Harbor Unit police officer Tommy Le who is an EMT. Tommy Le was able to apply a tourniquet."

"He was lying on top of the kayak and there was this pool of blood and we knew that we had to go over there and assisted him priority," the EMT said. No one else was seriously hurt and the investigation is ongoing.

Authorities say the ferry captain tested negative for drugs and alcohol.

A spokesman for New York Waterway says the company is cooperating with police and the U.S. Coast Guard.