Officials say pipeline safety regulators and Puget Sound Energy have reached a settlement over a complaint regarding a natural gas explosion in the Greenwood neighborhood of Seattle last year. The state Utilities and Transportation Commission said Tuesday the settlement would impose a penalty of $2.75 million with $1.25 million suspended if Puget Sound Energy completes an inspection and remediation program. Officials said the March 9, 2016 explosion that injured nine firefighters and damaged about three dozen businesses was caused by damage to an above-ground service line in an area where a pipeline was left active despite being abandoned in 2004.