A 35-year-old maintenance worker at the National Gallery of Art was critically injured yesterday when he fell 70 feet from the attic of the East Garden Court to a marble floor below, officials reported.

Jerry Abney of 905 Marcy Ave., Oxon Hill, was listed in critical condition at George Washington University Hospital, where he was being treated for internal injuries, broken legs, a broken wrist and a broken pelvis. t

Joseph English, administrator of the gallery, said the accident occurred at 9:05 a.m. Abney was above the glass skylight cleaning a pane when he fell through the glass, English said.

"We never considered it hazardous," said English. He said the skylights routinely have been cleaned twice a year since the gallery opened in 1941. He said the workmen cleaning them work from a trolley.

English said there were three to four other men near Abney when he fell, but it was unclear yesterday what caused him to lose his balance.

He said Abney, who has been working at the gallery for 4 1/2 years, landed feet first on the marble floor and did try to get up.

"It's very unfortunate," English said. "Nothing like this has ever happened."

The U.S. Park Police, who said they were notified of the incident yesterday afternoon, are investigating the accident, a spokesman said.