BOISE -- No one was hurt when a Boise Bench apartment complex caught fire Friday, thanks in no small part to citizens who sprang into action to get residents out of the burning building.

The fire started near the Parkwood Apartments at 4892 West Clark Street at about 10:45 a.m., putting off a thick column of black smoke that was visible for miles.

Rick McKenzie, who works at Miracle Tire across the street, said the blaze apparently began in a pile of wooden pallets next to Snake River Pool and Spa.

"When I came out of the office, I glanced over here and noticed that this stack of pallets was burning pretty good," he said.

Flames were already moving up the wall of the fourplex.

"It was an inferno within minutes," McKenzie said, estimating flames leapt more than 100 feet in the air.

He and another coworker calling 911 and ran toward the burning apartments. The pair banged on doors and windows to alert the residents, most of whom had not yet noticed the fire.

"Smoke was getting pretty intense in between the two apartment complexes there," he said. "My boss was going through the upstairs and I was going through the bottom stairs, beating on the sliding glass doors to the point where we were cracking them."

At one point, McKenzie said, he spotted an elderly woman on oxygen trying to get back into her unit. He was able to get he away from the burning building, guiding her down the street towards paramedics.

Nathaniel Rokovitz said he was riding his bicycle when he saw the smoke pouring from the building.

"I came around the corner a little bit more and I saw a couple guys from the tire shop go running toward the building, so I took off on my bike to go help out," he said.

Rokovitz said he pounded on doors to alert people inside the units.

All of the residents made it out safely, Boise Fire said.

In the past, Rokovitz said, he had just acted as an onlooker to dangerous situations, watching or recording on his phone. This time, however, "bravery kicked in," he said.

"I'm proud that I didn't just stand by and watch when there were people in danger this time," he said. "If I was in a situation like this and I didn't know, I'd want someone to come pounding on my door."

According to Boise Fire, three of Parkwood's fourplexes were involved in the fire. One of the fourplexes burned, and another has smoke damage. Six the apartments are not habitable.

The extent of the damage is unknown, and its unclear when or if residents will be allowed to move back in. The families will be assisted by the Red Cross and the Boise Burnout Fund

A third complex sustained minimal damage, and no residents in that complex were displaced.

One firefighter suffered a shoulder injury, and he is being evaluated.

Snake River Pool and Spa also sustained damage, losing 40 hot tubs to the fire.

Investigators are looking at security footage from the business to try to determine how the fire started.