Published: Aug 30, 2011 11:09 AM EDT
Updated: Aug 30, 2011 2:58 PM EDT

WASHINGTON (AP) - A federal safety panel plans to reveal the results of a yearlong investigation into a natural gas pipeline explosion near San Francisco that killed eight people.
 
The accident last September incinerated a suburban neighborhood and prompted a national reevaluation of pipeline safety.
 
Investigators for the National Transportation Safety Board will lay out their analysis Tuesday of what caused the rupture of a large Pacific Gas & Electric Co. transmission line buried beneath the community of San Bruno, Calif.
 
The explosion sent a giant pillar of fire into the air that continued to burn like a massive blowtorch for an hour and a half before PG&E employees were able to shut off the flow of gas.
 
It was the worst pipeline accident in a decade.