The Philadelphia Office of the Fire Marshal determined that lightning caused the rooftop fire at a vacant building near the intersection of 16th and Oxford streets on Sept. 2.
Lightning struck the building and caused a small fire that went unseen at first, said Kathy Matheson, a spokesperson for the fire department.
“It kind of smoldered unseen until it got large enough to be noticed,” Matheson said.
The blaze eventually consumed the entire building’s roof and could be seen from blocks away. The fire department shut off nearby blocks to pedestrian and vehicle traffic until the early hours of the morning as they tempered the blaze.
The fire department asked students and residents in the immediate area to evacuate until an all-clear was issued the following morning. Temple counted approximately 100 displaced students who sought assistance during the fire, 10 of whom the university helped find alternative housing arrangements.
No injuries were reported.
The four-story building had been under construction, said Deputy Fire Commissioner Craig Murphy at a press conference the night of the fire.
PECO briefly cut power to the surrounding area, which included some student housing complexes, in order to avoid complications for firefighters who were extinguishing the blaze.
Natural causes, which include lightning, led to 1.6 percent of all residential fires in the U.S. in 2017, according to the U.S. Fire Administration.