Welding sparks apparently ignited a pile of metal shavings that started a massive fire in an industrial area northwest of downtown Phoenix. The fire snarled traffic near "The Stack" interchange of Interstate 10 and Interstate 17 on Thursday.
The Arizona Department of Transportation said Friday the elevated ramp connecting I-10 with I-17 at the interchange was not damaged from the heat or smoke from the blaze.
No traffic restrictions remained from the fire on Friday morning.
Phoenix fire Capt. Jonathan Jacobs said two welders were working when some of their sparks landed on a pile of highly flammable titanium shavings. He didn't specify which business they were in, but one business owner said the fire started at Mega Metals, Inc., next to his business, and quickly spread.
Jacobs said there were four to six explosions at Breecher Sales located at 1300 N. 21st Ave. believed to be caused by some metals reacting to the fire, which was putting out a lot of heat.
Co-owner Sam Breecher said he was in his office when someone knocked on his door and yelled for him to get out. He said the flames started next door at Mega Metals. Breecher and his employees were not injured.
The blaze consumed three structures on the same business lot within a 20-minute timeframe, according to Jacobs.
Jacobs said firefighters used a "stand back" strategy against the fire and were able to gain control of the fire about 3:15 p.m. Firefighters still had a boundary set up between the fire and other structures to prevent property loss.
"There's a lot of structure that is burning, but we just don't know what is stored in the structure," Jacobs said.
He said the fire involved multiple materials, such as compressed gasses and flammable metals in the immediate area, and was extremely dangerous for firefighters.
Jacobs said firefighters were fortunate the thermal column went up in the atmosphere and didn't blow into the city.
Two workers escaped the area and are working with fire investigators to pinpoint what happened. One of the workers was taken to the hospital with minor burns.
HAZMAT crews monitored air quality, and Jacobs said the only problem area was inside the "hot zone."
Approximately 60 firefighters responded to the fire, including ladder trucks that were pouring about 2,000 gallons of water a minute on the flames.
Flames and thick black smoke were seen billowing above the northbound exit of I-17 off westbound I-10 starting about 11:45 a.m.
Numerous businesses were evacuated by 12:30 p.m., Jacobs said.
Jeff Olson of All Star Catering said he reported the fire to a dispatcher just before 11:45 a.m. Olson witnessed two large explosions as he was talking with CBS 5 News about 12:10 p.m.
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