No gas odors were reported prior to this morning’s event and BGE did not receive any recent gas odor calls from the block of homes that were damaged.
Police said at least three shooters may have been involved, though no arrests were immediately announced.
A fourth house in the row was partly destroyed, and the neighborhood was strewn with glass from shattered windows.
U.S. officials said the administration also plans to provide at least $15 million in disaster assistance.
French and Russian rescue teams with dogs were searching the port area on Friday.
Some other recent deadly explosions involving ammonium nitrate.
A senior U.S. Defense Department official and member of the U.S. intelligence community said there were no indications the massive explosion that erupted on Tuesday evening in Lebanon’s capital was the result of an attack.
An official with the Lebanese Red Cross said at least 100 people were killed and more than 4,000 were wounded.
More than 70 people were killed and 3,000 injured, with bodies buried in the rubble, officials said.
At least one person was flown to a hospital in Idaho Falls.