Construction crews working at the site of a new apartment building in Philadelphia found dozens of coffins — some nearly 300 years old — KYW reported, bringing work to a standstill.

The coffins had been interred in the First Baptist Church Burial Ground, a cemetery that was established in 1707, KYW reported. Records show the bodies, which include children and adults, should have been moved to the Mount Moriah Cemetery in southwest Philadelphia in 1860, but apparently the job was never completed.

“It’s a business unfortunately and sometimes it’s cheaper to cut corners in a business,” Dr. Lee Arnold of the Historical Society of Pennsylvania told KYW.

The construction site is the future home of a 10-story, 116-unit apartment building with two underground levels of parking. The building is scheduled to be completed by April 2018, KYW reported.

Officials said that the process of excavating the coffins should be completed by the end of the day Saturday.

“We’ll try to find out anything that these bones can tell us about who these people were in life,” Kimberlee Moran, an associate teaching professor and director of forensics center at Rutgers University, told KYW.

“This is a rare opportunity to learn as much as we can about the earliest residents of Philadelphia. Ultimately, we want to reinter them at Mount Moriah Cemetery with the rest of the remains from this time period,” she said. “If there are any living descendants, we are going to try to identify them.”

After research is complete, the remains will be reinterred at Mount Moriah Cemetery. PMC Property Group Executive Vice President Jonathan Stavin, whose company is constructing the apartment building, told KYW that the company will take care of those costs.