A 37-year-old woman walking down the street talking on a cellphone in

A 37-year-old woman walking down the street talking on a cellphone in the West Village was killed in a freak accident when she was struck by a giant piece of plywood that was ripped off a fence by a wind gust, authorities said Wednesday.

The 4-foot-by-8-foot, green-painted board sailed 50 feet across West 12th Street and hit real-estate agent Tina Nguyen so hard that it threw her against a building, where she smashed her head on an FDNY stand pipe.

Nguyen, who worked for the Park Avenue firm Keller-Williams and who was engaged to be married, was pronounced dead Tuesday at Bellevue Hospital shortly after the 6 p.m. tragedy.

Winds were gusting up to 40 mph hour at the time. The plywood board was ripped from a street-level security fence surrounding a luxury condo-construction site on the lot where St. Vincent’s Hospital once stood.

Paramedics found Nguyen lying in front of a parking garage with severe head and body trauma.

Eric Jana, 33, who lives in the building that Nguyen was thrown into, said, “It’s frightening .?.?. This was just a terrible freak accident.”

Poor girl!!