A young construction worker from Ecuador pleaded guilty yesterday to strangling an actress in her West Village apartment and then hanging her to disguise the murder as a suicide.

“When she fell to the floor, I was very scared,” the laborer, Diego Pillco, 20, said yesterday in state Supreme Court in Manhattan, where he pleaded guilty to manslaughter for the killing of actress Adrienne Shelly. “I saw a sheet and I decided to choke her and that’s what happened.”

Pillco offered these words in a whisper. A translator amplified the narrative to the courtroom in a loud, upbeat voice.

At times Pillco fell silent and appeared to have nothing more to say. The judge, Carol Berkman of state Supreme Court in Manhattan, pressed him on.

“And then you tied the sheet around her neck and strung her up?” the judge asked.

“I made it like she committed suicide on her own,” Pillco said. “I just want to ask forgiveness from her family.”

As part of a plea deal, Pillco will receive 25 years in prison.

Pillco, who was renovating an apartment in the same building where Shelly lived, said that he had set out to rob Shelly and followed her to her apartment. A fight ensued.

“Out of desperation I got scared and I covered her mouth,” he said. “I was so nervous, I didn’t realize what was happening to her.”

Shelly, 40 at the time of her death, had appeared in several independent films.