Construction crews were back to the work at the new CareSource building in downtown Dayton Friday a day after a fire on the roof Thursday.

CareSource construction fire in downtown Dayton ruled accidental

Firefighters responded to the site on the corner of First and North Jefferson streets around noon on Thursday after insulation roofing material being used for construction ignited.

Dayton fire spokesman Bryan Adams said the fire was related to the construction work at the site, but couldn’t comment further since the investigation is still considered open.

RELATED: Dayton official: CareSource construction site fire ‘not dangerous’

The fire sent a large column of pitch-black smoke billowing, visible as far away as Troy and Beavercreek. 

PHOTO GALLERY: CareSource construction fire

Traffic in parts of downtown came to a standstill as officials blocked off streets for safety and as crowds formed to watch the spectacle. 

“Pieces of charred black material are floating off the building and landing on the street,” said Steve Brack, a GrubHub driver that was making lunchtime deliveries downtown.
RELATED: CareSource responds to fire at construction site

The building will be first newly constructed office tower in downtown Dayton in about a decade.

According to Dayton fire officials, everyone was able to get out of the building safely, and the only people believed to have been inside at the time the fire started were construction workers.

The heavy black smoke rising over downtown may have looked dramatic, but the fire was not particularly large or hazardous, said Dayton fire Chief Jeffrey Payne.

“This wasn’t a dangerous fire because it was outside and well ventilated,” he said.