PHOENIX — Crews fought a second-alarm fire at a building near Grant Street and 7th Avenue in downtown Phoenix Sunday night.
Firefighters said the building that caught fire was still under construction.
About 200 firefighters responded to the blaze at the four-story apartment complex, which was about 40% built.
The fire was spreading east toward other buildings, but fire crews were able to protect them.
The flames burned scaffolding and construction equipment and caused a power outage.
APS crews were on scene for hours trying to get power restored to the area.
Witnesses tell 12News they heard several explosions while the fire was burning.
"It's scary, it's pretty scary, it's scary to see all that," one resident said.
He and others who live in the area were terrified of the growing fire right outside their homes.
"At first I thought it was protestors that's what I thought, but we don't have a clue what's going on," he added.
Meanwhile, the raging flames ignited the existing building, multiple fire crews worked into the overnight hours putting it out.
At one point, construction equipment was used to pile up burning debris, in hopes of putting out the flames faster.
"When I first came here it was one or two fire trucks, now we have one, two, three, four, five, six, about 15, it shut down the bridge to traffic because of the fire," one witness said.
The massive flames and thick smoke continued smoldering at the construction site near Seventh Avenue and Grant Street, another man described what he'd seen.
"I live right back behind your camera there and I heard five separate explosions. I'm fearing for my safety, I'm going back home," he said.
The Phoenix Police Department said Monday morning that a man was arrested in connection to a nearby shooting, but later clarified that there was no shooting that occurred at or near the fire.
There was an argument between some armed people and there were arrests related to that, police said.
The cause of the fire is not yet known. It was contained early Monday morning, but firefighters still worked to put it out.
The fire department also said burning construction equipment on scene caused many of the explosions.
There were rumors going around that an APS substation was on fire, but an APS official said that was not the case.
This is a developing story. Check back here for updates when we learn more.