A construction worker severed his hand in a horrific accident today on Staten Island, sources said.

Steven Selva, 20, was doing outside repairs on a home at 24 Kelvin St. in Bay Terrace at about 5:30 p.m. when he fell about 20 feet from a ladder and a power saw lopped off his left hand at the wrist, according to sources.

Selva, of Newark, was rushed to Bellevue Hospital with a police escort.