PORTLAND, Ore. » A powerful natural gas explosion rocked a busy Portland, Oregon, shopping district today, injuring eight people and igniting a fire that sent a huge plume of smoke over the heart of the city.

Three firefighters, two police officers and three civilians were hurt, and one of the firefighters was still in surgery late Wednesday for a broken leg, fire Chief Mike Myers said at a news conference. None of the injuries appeared to be life-threatening.

A building that housed a bagel shop and a beauty salon in the popular NW 23rd Street shopping district was reduced to rubble, and its smoldering roof was splayed across the road.

The windows of a nearby building were blown out and debris was everywhere. Firefighters swarmed the scene and dumped water from ladder trucks onto the smoking wreckage.

NW Natural released a timeline saying the explosion occurred at 9:38 a.m. — a time when many businesses were still closed.

City officials said a catastrophe was averted by speedy work from firefighters and police who responded to a reported gas leak and cleared the area of people before the blast.

“There are a lot of people alive” who might not be “but for the excellent work by our first responders,” Mayor Charlie Hales said.

One young fire lieutenant in particular — the same one with the badly broken leg — made several critical decisions that likely saved lives, Myers said.

Fire Lt. Peter St. John positioned fire trucks and hoses in such a way that they were out of the blast zone and ran into the building to pull fire alarms when firefighters realized not everyone had evacuated as ordered, Myers said, adding that the man was new to the fire department.

“That man saved the lives of a lot of people today and a lot of firefighters,” the chief said.

Firefighters also donned their air packs and masks before the blast, an unusual move for a routine gas leak call, but one that also prevented serious facial injuries, he said.

Portland’s NW 23rd Street — nicknamed “Trendy Third” — is packed with boutiques, bars and restaurants. Many are on street level with pricey apartments on the upper levels and a day care facility in the vicinity.

The utility said it got a call at 8:55 a.m. saying a construction crew had hit a gas line. Authorities and utility workers responded in 15 minutes and evacuated the building, NW Natural said in its statement.

People in the neighborhood reported smelling gas as they were evacuated and later felt the explosion.

The utility hasn’t determined what caused the gas to ignite, but NW Natural CEO David Anderson said it was a rare event that required a certain amount of ambient gas, an enclosed space and an ignition source.

An employee at a nearby kitchen accessories store said he was in the washroom when he felt a huge explosion and emerged to find thick smoke and haze. Scott Bergler said 15 windows in the first-floor store were blown out.

As he evacuated the Kitchen Kaboodle shop, Bergler saw a firefighter on the ground who had been knocked flat by the blast.

“He was obviously in shock and crawling and having a hard time standing up,” said Bergler, who remained shaken by the ordeal as he gathered with co-workers in a parking lot.

Nicole Christiansen climbed exterior stairs to a rooftop of a nearby building so her 2-year-old son, Theo, could see everyone was safe.

The child had been evacuated from his day care center just before the blast, but he heard the explosion and was scared, she said. He looked on with wide eyes and clutched a crumpled napkin from an unfinished snack as firefighters poured water on the building.

“I saw the smoke from way down the hill, and I realized he was impacted,” she said. “He has to go home.”

About 2,000 people remained without power and authorities weren’t allowing people back into apartments, homes and businesses overnight.

“They’re going to be displaced for a long time and there are great little businesses that are going to be closed for a long time,” Hales said.