Utility crews have found a total of eight natural gas leaks in the north Seattle neighborhood where a home exploded, injuring two residents in a two-alarm fire.
The pipes have been dug up for repair, Puget Sound Energy spokeswoman Martha Monfried said Tuesday.
More than two dozen utility employees were using sniffer equipment to sweep the area within five miles of Monday's blast.
Four of the leaks have been linked to electrical arcing initiated when a tree knocked down a high-voltage power line Sunday. The utility believes this is what caused the holes to the service line of the destroyed home.
One leak is under investigation and the other three are not related to the downed tree.
Puget Sound Energy said it surveys its entire coverage area every day with trucks and people. The utility has conducted extra surveys over the last two days in a 5-square mile area near the site of the explosion.
David Ingham, one of the two people injured in the explosion and fire has been released from the hospital, Harborview Medical Center spokeswoman Susan Gregg said Tuesday. Ingham's wife, Hong, remains in serious condition in the intensive care unit.
Damage from the blast is estimated at $350,000, Fire Department spokesman Kyle Moore said.
The utility has 750,000 natural gas customers in five counties.