Everett, WA – he explosion that damaged 36 businesses and injured nine firefighters in north Seattle last week had something in common with a 2013 blast at an Everett home.

Both occurred after natural gas leaks.

Pipeline safety engineers from the Washington Utilities and Transportation Commission and Seattle firefighters continue to investigate Wednesday’s explosion in the Greenwood section of Seattle. Three businesses were destroyed and the blast broke windows blocks away.

In April 2013, a man scrounging for scrap metal inside an abandoned house in the 1200 block of 41st Street lit a cigarette after cutting into pipes carrying natural gas. He heard a hissing sound.

The house exploded, the foundation cracked and windows shattered, but the man managed to escape only with singed eyelashes.

“It was nothing of the magnitude of what happened in Seattle,” said Eric Hicks, Everett Fire Department fire marshal.

There usually are warning signs with natural gas leaks, Hicks said.

Often there is a sulfur, rotten-egg smell and hissing sounds.

In such circumstances, Hicks said people should leave the area and call 911.

It’s also important not to light a match or smoke a cigarette because that can spark an explosion.

Snohomish County Fire District 1 often gets calls about natural gas leaks, agency spokeswoman Leslie Hynes said.

“I don’t know if it’s every single day, but we get quite a few inside and outside of buildings,” Hynes said.

Larger leaks often are related to construction projects when pipes get ruptured.

Smaller leaks frequently occur inside homes.

For those, “it’s better to get a technician in there, someone who knows what they are doing,” she said.

Natural gas is prevalent in many parts of the state.

The Utilities and Transportation Commission’s pipeline safety program regulates safety practices of 31 pipeline operators and does inspections on more than 41,000 miles of gas and hazardous-liquid pipelines across the state.

Even a small amount of volatile gas can explode with deadly results. Barista Courtney Campbell died in January after an apparently faulty propane heater caused an explosion at the Sinners and Saints Coffee Co. along Everett Mall Way.