Criminal investigators say a natural gas leak caused a house explosion in Fitchburg last August, but there are still questions about what led up to it.
The state Justice Department has issued a summary of its probe into the August 2016 incident that injured Brian Grittner who lived there and damaged more than 20 homes nearby. The explosion destroyed the home of the 57-year-old Grittner.
The Justice Department says questions remain about a valve he turned on before the blast — and whether it was a gas valve or a water spigot.
Gritter filed a civil suit last fall, claiming an installer did not properly put a cap on the gas line after an old gas dryer was replaced with an electric unit in 2011.