ABINGTON TWP., Pa. -- A massive fire tore through an industrial complex in Abington Township, Pennsylvania on Monday night.
A shelter-in-place order initially was in effect until the incident was under control because smoke and particulates from the fire were filtering across the area, officials said. But residents and businesses in the immediate area near the plant - roughly 700 people - were asked to voluntarily evacuate late Tuesday afternoon "while conditions permit" because of concerns over air quality.
The fire broke out around 9:43 p.m. Monday at SPS Technologies, located in Montgomery County.
Many roads in the area remain blocked off as crews target hot spots.
Black smoke could still be seen billowing out of the building Tuesday afternoon, more than 13 hours after the first alarm.
"There's nothing more important than protecting the members of our community," said Abington Police Chief Patrick Molloy when speaking about the voluntary evacuations that impact about 247 homes.
The view from ABC Philadelphia affiliate WPVI's helicopter on Monday night showed heavy flames consuming the property.
Officials said the building was immediately evacuated, and all occupants have been accounted for.
People nearby rushed out of their homes to see what was going on. Some witnesses reported hearing explosions.
Officials said 68 different fire companies in the area responded to the scene.
Aqua, SEPTA, as well as Pennsylvania and federal EPA officials are on site. Departments of public safety from Bucks, Montgomery and Chester counties also responded.
The flames caused explosions, and what's inside the industrial complex is of great concern to county officials and residents.
Any residence or business within a one-mile radius of the complex should remain closed until further notice.
That guidance covers around 17,000 residents.
"What's burning? What's in the air? What are we breathing in? How long is this going to go on for?" asked Maria Duffy, from Glenside, who is sheltering in place with her family.
Hazmat crews are continuing to monitor air quality and runoff water in the area. So far, officials say tests have not detected any threats to the public.
"We had concerns that if some of the chemicals were to mix, it could form arsenic which could get in the air and in the smoke that's coming off the fire," Abington Fire Chief Mike Jones said.
The city of Philadelphia said they are also monitoring the air quality from the fire event.
"It could be weeks before you see the effect of this type of exposure," said Dr. Jamie Garfield, a Temple Health pulmonologist.
Two years ago, SPS technologies had to pay a fine of $109,000 to the EPA, for failing to properly dispose of and store hazardous waste, as well as failure to have a clear contingency plan for evacuation.
Some schools will be closed Wednesday, and some train service is affected.
No injuries have been reported; although, officials said there are concerns after first responders were exposed to the hazardous materials.
The cause of the fire is still under investigation.
According to its website, SPS Technologies manufactures fasteners and other components for aerospace, transportation, racing, farm and industrial markets.