An elderly man was critically injured when he fell onto the tracks and was struck by a train Wednesday morning on the Upper West Side, police said.

The 76-year-old straphanger was standing on the platform of the uptown 1-train at the 66th Street-Lincoln Center station around 10 a.m. when he suddenly became disoriented, cops said.

The unidentified man fell onto the tracks and was struck by an oncoming train.

He was rushed to NewYork-Presbyterian/Weill Cornell Medical Center, where he remained in critical condition.