Sam Phillips Saved From Frigid East River By FDNY, NYPD After Homemade Raft Deflates (VIDEO)

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Emergency responders rescued a teen stranded in the East River Thursday night after his homemade raft deflated.

Firefighters received a call at about 6PM for a person in the water at 87th Street near Gracie Mansion. Arriving at the scene, they found 18-year-old Sam Phillips, who had been riding his DIY 15-foot Zodiac-type raft in the 43-degree water.

Cops had spotted the teen as well and tossed him a life ring from a 40 foot seawall.

"We witnessed a person in the water struggling, hanging on to a life ring supported by a rope over a sea wall 40 feet in the air off the East River Drive," Michael Krochak of Marine Unit 6, told NBC New York. "That was the only thing he had for support at that point."

Phillips had been in the water 20 minutes when Krochak dove in and grabbed him. Another diver then hoisted them onto an FDNY boat.

Phillips was not seriously hurt but was taken to the hospital to be checked for hypothermia. Krochak called him a "lucky kid."

Fire officials tell NBC New York "it appeared the man was attempting to test out a homemade raft."

It was the second water rescue performed Thursday. In the morning, members of the NYPD Emergency Services Unit saved a woman who drove her car into the Hudson River.