Two people were killed and at least four injured yesterday afternoon when an Allegheny Airlines plane bound for Washington crashed during a snowstorm after takeoff from an airport in Clarksburg, W. Va.

The plane, Allegheny Flight 560 from Clarksburg to Washington National Airport with a stop in Morgantown, W. Va., carried 22 passengers and a crew of three.

An Allegheny spokesman identified the two dead persons as David Baltes, of Beaver Falls, Pa., the planes' first officer, and Mary Sturm, of Fairview, W. Va., a passenger.

"We have everybody out of the airplane and all of the other people are ambulatory," an official at Benedum Airport in Clarksburg said. The crash occurred about 1:10 p.m.

The plane came to rest about 100 feet from the end of Runway 21.The snowstorm was of such intensity that the crash could not be seen from the control tower. Federal Aviation Administration officials said that visibility was five-eighths of a mile in a 1,000-foot overcast, within permissible limits.

"We had started rocking from one side to the other and then the wings hit the ground," Iris Baisden, a surviving passenger, told the Associated Press. The plane, she said, "flipped over, went over on its top."

Bob Fry, FAA supervisor at the air traffic control tower, said the plane lifted off the ground, then disappeared into the snow and clouds.

"After he was no longer visible from the control tower, the controllers heard an emergency signal," Fry said, "and as soon as they did it sort of alerted them to the fact hey, you know, Allegheny's having a problem."

Controllers contacted the Cleveland (Ohio) regional air traffic control center to see if the plane was showing on radar. When they received a negative reply, trucks were dispatched and the crash was located.

There were conflicting reports from the scene as to whether the runway had just been plowed free of snow before the takeoff, or whether plowing was just beginning at the time of takeoff. In any event, the two-engine turboprop M298 was about three hours behind schedule.

The National Transportation Safety Board dispatched an investigating team to the scene last night.