A large boom from a test explosion at Aberdeen Proving Ground yesterday afternoon apparently rattled some homes -- and nerves -- in Cecil, Harford and Kent counties.
Base officials said the test of a 1,000-pound explosive charge was conducted at 4:10 p.m. The resulting vibration shook pictures from their walls, some residents said.
The blast occurred about the same time as warning sirens were being tested by the Maryland Emergency Management Agency.
The sirens, which are to be installed at the base this year, are part of a plan to increase emergency preparedness in the event of an accident involving the base's stockpile of 1,500 tons of mustard agent.
Army spokesman Gary Holloway said base officials received at least two dozen telephone calls after the test explosion.
A smoky brush fire at the Edgewood Area of the base started about 1 p.m. Smoke could be seen for miles, witnesses said.