A 57-year-old man was found in flames and screaming in pain on a Staten ­Island street Saturday.

It was unclear how John Quattrocchi caught fire, but a law-enforcement source said it may have been a suicide attempt. He was in critical condition at Staten Island University Hospital North.

Firefighters rushed to Driprock Street and Post Avenue at 9:49 a.m., smothering the blaze with blankets.