A state investigation into the late winter Greenwood gas explosion has found the likely cause to be accidental damage to a supposedly retired natural gas line, owned by Puget Sound Energy, from people using the alley between Mr. Gyros and Neptune Coffee.

The report further accused Puget Sound Energy for “improper abandonment” of the service line and recommended the utility company be fined up to $3.2 million.

“The leak and explosion would not have occurred but for PSE’s improper abandonment of the service line in September 2004,” wrote pipeline safety director Alan Rathbun and utilities engineer Dave Cullom in the report. “Staff’s investigation revealed that the service line had not been ‘cut and capped’ as documented by PSE’s contractor Sept. 1, 2004. As a result … the service line remained operationally active until it was shut off after the explosion.”

In a response to the Commission report, spokespeople for Puget Sound Energy called the recommended fines "disappoint and excessive."

At 1:04 a.m. on March 9, a 911 caller reported a gas leak to the Seattle Fire Department via 911. The caller directed firefighters to the alley on the west side of the 8400 block of Greenwood Ave. N., where they determined gas was escaping from a threaded coupling on the exposed service line.

At 1:43 a.m. the gas ignited, causing an explosion that injured nine firefighters. The buildings housing G&O Family Cyclery, Neptune Coffee, Mr. Gyros and Greenwood Quick Stop were destroyed in the explosion and more than a dozen nearby businesses sustained damage. Puget Sound Energy staff deactivated the line by 7:28 a.m.

In the immediate aftermath of the explosion, the state Utilities and Transportation Commission dispatched investigators to the scene. Puget Sound Energy also hired investigators to interview witnesses and review the physical evidence at the scene.

Interviews revealed that individuals were using the alley to store items like bags, backpacks and bicycles. Interviewees said they would sometimes trip on the gas line. The threaded, leaking coupling was one- to two-feet above the ground.

Puget Sound Energy spokespeople placed blame for the explosion squarely on the damage caused by these people.

"All parties investigating the March incident, including the UTC and the Seattle Fire Department, agree: the natural gas system at the Greenwood site was damaged by unauthorized individuals in a space not intended for human activity, with the resulting gas leak causing the explosion and fire," spokespeople said.

But that leak would not have been possible if Puget Sound Energy had followed regulations for defunct lines, investigators said.

Records from Puget Sound Energy claimed the line was disconnected and sealed when it was retired in 2004.

Investigators determined that was not true, and the line had remained active for nearly 12 years.

Because the line was listed as retired, Puget Sound Energy failed to conduct the leak surveys and corrosion tests required of active lines.

In all, Commission staff found the energy company violated five state and federal regulations regarding gas lines. They recommended the Commission lobby penalties up to $3.2 million.

The investigators’ complaint will be heard by the three members of the Utilities and Transportation Commission, who will determine Puget Sound Energy’s final penalty.