SANDY, Utah - Construction crews working on a gas pipeline have discovered the remains of an ancient civilization in Sandy.

Officials said crews working on a Questar gas line in the Sandy area uncovered something that caught an environmental worker’s attention, black stuff.

Workers said they thought the soot-stained rock and charcoal debris could be evidence of an ancient fire pit or a pit house and closer inspection confirmed that theory.

“This is exciting,” Laura Springsteen said, environmental coordinator for Questar Corp. “We hired archaeologists who began working the site last Friday. They removed the overburden and overlying deposits and set up a grid for the excavation areas.”

Archaeologists first estimated the site was about 3,000 years old but after finding more remnants like chipped rocks, animal bones and an obsidian cutting tool or hunting tip, they suggest the site may be about 1,500 years old.

Crews found more projectile points, stone tools, flakes and large quantities of animal bones Tuesday.

Archaeologists said they expect to complete the excavation work this weekend and bury the site.

Researchers will study the artifacts and try to learn more about the people who inhabited the site in Sandy.

Officials have not confirmed the exact location in an effort to preserve the site. FOX 13 News' Todd Tanner was live at the scene Wednesday, see the video above for his report.