Investigators from the Baltimore Gas and Electric Co. and the Maryland Public Service Commission returned today to a house in the Irvington section of southwest Baltimore in hopes of finding the cause of an explosion yesterday that killed an elderly woman and injured two other people.
Art Slusark, a BG&E spokesman, said last night that initial investigation by experts yesterday found no evidence a natural gas leak caused the explosion that destroyed the home at 321 Martingale Ave. and killed its occupant, Marian Wilderson, 85.
Capt. Patrick P. Flynn, a spokesman for the city fire department, said today one strong possible cause of the blast was that Wilderson turned on a gas appliance -- most likely the stove -- and did not immediately light the gas source.
Flynn said the gas could have built up to the point where a tiny spark could have caused the powerful explosion that was felt for blocks around.
Preliminary information shows that there were no specific gas leaks coming from the house or other residences in the neighborhood, Flynn said.
City fire officials said yesterday Wilderson, a widow, may have set off the explosion when she turned on a basement light while investigating a strong odor of natural gas. A spark from the light switch probably triggered the blast, fire officials said.
The explosion damaged two other Martingale Avenue homes, one extensively.
"All of our preliminary investigations following the explosion have failed to reveal that the incident was caused by a gas leak," Slusark said.
He said that as best as can be determined, all BG&E equipment and lines in the house and underground were in "good working condition."
Slusark said investigators would continue checking the natural gas pipe lines leading into 321 Martingale, the gas meter and any gas-powered appliances to see if there are any signs that gas was leaking before the explosion.
"We did receive a call at 9:51 a.m. from a resident at 317 Martingale Ave. reporting a strong odor," Slusark said, "but the caller did not identify the odor as gas."
The explosion, about 10 a.m. yesterday, occurred as a BG&E crew was on its way to investigate the report.
Slusark said PSC investigators told the utility's work crews at the scene that the explosion "could be gas-related," but that there was no hard physical evidence that a gas leak actually was the cause.
He said BG&E records are being checked to determine if Martingale Avenue has a history of gas leaks.
"Right now, it doesn't appear that the neighborhood was prone to have gas leaks according to our records," Slusark said.
The explosion woke Robert Tabor, who didn't know what the noise was at first, "But I knew it was real close."
Tabor, of 356 Marydell Road, looked out the bedroom window at the back of his house and thought he saw snow. Then he spotted a small fire amid the ruins of what had been an end-of-group home across the alley, at 321 Martingale Ave.
He realized it wasn't snow falling from the sky. It was foam insulation from the demolished house.
Wilderson's brick and cinder-block home was leveled by the explosion, which also caused extensive damage to the houses at 319 and 323 Martingale Ave.
Residents of about 50 rowhouses on Martingale Avenue and Marydell Road, just south of Frederick Avenue, were evacuated as city police and firefighters and Baltimore County firefighters worked at the scene. By 11 a.m., more than a dozen vehicles of the city police department and fire department and the county fire department had arrived. Frederick Avenue from Athol Avenue to just west of Martingale Avenue was closed to traffic for several hours.
Debris from the explosion -- wooden beams, slate roofing, window screens, broken glass, clothing and furniture -- was scattered up to 100 feet from the site of the blast. Much of it came to rest on bushes and rooftops on the opposite side of Martingale Avenue.
Wilderson was described by neighbors as a recluse who lived alone. She had lived in the house for nearly 45 years. Her body was removed from the wreckage by firefighters and she was pronounced dead about 2:15 p.m., a little more than four hours after the blast.
Samuel Bianco, 74, of 323 Martingale Ave., an end-of-group house just south of Wilderson's, was taken to the University of Maryland Medical Center, where he was treated for facial cuts and a broken nose. Bianco was in good condition today, said a nursing supervisor at the hospital. She said Bianco would stay at the hospital indefinitely for tests to determine if he had neurological damage.
Kathleen Billmyre, 70, of 338 Marydell Road, just across the alley from the explosion, was taken to St. Agnes Hospital for a hand injury. She was treated and released, said hospital spokeswoman Anna Gable.
An unidentified firefighter was treated at a hospital for what department officials called "minor injuries." He was later released.