New York- A transgender porn actress plunged to her death from a luxury Chelsea apartment building early yesterday, apparently a suicide, cops and a friend said.

The 36-year-old Mexican immigrant fell 20 floors from the 30-story Vanguard Chelsea on W.24th St. at the corner of Sixth Ave., landing in the street about 4:30 a.m., police sources said.

According to a close friend and business partner, Susan Shah was suffering from a life-threatening illness, but had been in good spirits recently.

“I talked to her yesterday and she was in Times Square having a blast with a friend,” said John Tennler, 40, a filmmaker from San Francisco.

No note was found in the 20th-floor apartment where she lived.

Tennler said Shah, who starred in at least three porn flicks, was taking film classes at NYU.

An NYU spokesman could not confirm that Shah, who called herself “Princess Shah” on her Web site, was a student. Several NYU students have committed suicide since September last year.

At one point, Shah worked as an escort, according to the Web site, which is filled with nude photographs.

She lived with a boyfriend, who helped put her through school, Tennler said. “She was the sweetest, most generous person you ever met,” he said.