COLUMBUS, Ohio (WCMH) — After more than three days, a massive fire at a Columbus scrapyard is out, but work at the site for the Columbus Division of Fire (CFD) is not over. The fire started early Friday morning. CFD crews were still there Monday morning spraying water on the massive pile of debris.  “They’re continuing to separate material, the company is. And we’re just staying on site to make sure there’s nothing flaring up," CFD Chief Jeffrey Geitter said. Women accused in OSU Jewish center vandalism plead guilty CFD has 1,600 members, according to Geitter, who estimated more than 500 of them were involved in fighting the fire at the scrapyard on Alum Creek Drive. He also said staff rotated in and out every four to six hours. “It never really called for more pieces of equipment, it was more just trying to keep our crews fresh because we’re going to be here so long," Geitter said.  Watch: Work continues even after scrap fire extinguished Investigators will be trying to figure out what started the fire. That process could take days or weeks, according to Geitter. "This is going to be a hard one, needle in a haystack kind of analogy in the sense that there’s a lot of damage to junk, for lack of a better term, and trying to find what started it, it’ll keep our investigators busy," Geitter said.  Smoke from the fire could be seen and smelled in nearby neighborhoods. Although some residents told NBC4 they were not worried, others said they had health concerns. Tammy Stevens, who was watching her grandson, said she kept him inside with what was going on, Wendy's proposed to take over former Whitehall Bob Evans “I did talk to him and I said probably ought to watch out how much Jackson goes outside today, so that way he doesn't get any kind of respiratory infection or anything like that," she said. Over the weekend, CFD did recommend those in the area keep their windows closed. “It’s a fair question -- we all saw, that column was impressive to see," Geitter said. "Everything in this fire are things that do burn every day in this city, this was obviously a much larger amount of those things." The Ohio Environmental Protection Agency said no issues were picked up by its air monitors over the weekend. It also said the air quality index as of Monday afternoon was 82, which is considered "moderate (typical) air quality."