Firefighters in Philadelphia were working to extinguish a fire on the roof of a Center City building around lunchtime on Monday.
Fire could be seen growing along the roof of a building near the intersection of 12th and Sansom streets at about 12:35 p.m.
Officials have not reported any injuries in this incident.
Before 1 p.m., firefighters could be seen pouring water over the fire, which had expanded to a second alarm with about 100 fire personnel on the scene, according to the Philadelphia Fire Department.
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Within minutes, the fire seemed to be mostly put out.
A short time later, the fire was mostly extinguished and firefighters were reportedly checking the building for hot spots.
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Not long afterward, the fire department declared the incident under control.
According to fire officials, the fire took place on the roof of a 20-story structure that was under construction.
Also, propane tanks that were on the roof caused an explosion during this incident, officials said.
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