A Connecticut man desperately tried to save his dad from falling at an abandoned quarry — but they both ended up plunging 75 feet to their deaths, police and stunned co-workers said.

Steven Price, 71, of Bristol, and his son, Mark Price, 31, of Plainville, were riding all-terrain vehicles late Wednesday at the old Tilcon quarry in Farmington with another man when the elder Price stopped and walked toward the edge, their former boss told The Post.

“The father had walked over, about 7 to 10 feet from the edge, and then hit uneven ground,” Dan Siracusa of Siracusa Moving & Storage said Friday. “He then started to tumble and the son grabbed him, but they went down together and fell 75 feet onto rocky ledges and jagged rocks below.”

Siracusa said both men were very badly “smashed up” by the fall.

“It wasn’t a soft landing at all,” he said.

Steven Price had retired after working for 15 years with the company, but still did odd jobs and repairs. His son, Mark, had driven trucks for the firm for the last 10 years. Co-workers at the New Britain-based company were shocked by their deaths, especially the man who saw their fatal fall, Siracusa said.

“He’s very, very shaken, this kid,” he told The Post. “He watched his best friend die and he held him as he passed. Mark risked his life to save his father. He grabbed onto him and wouldn’t let go until the point that he got pulled down, too.”

Siracusa said the co-worker, whom he refused to identify, then rode his ATV to a nearby Subway restaurant and called cops.

“They need immediate help,” the caller told a dispatcher, according to WFSB. “They fell off the side of the cliff. His dad went to look at something, tripped — his went to grab him and they both fell.”

Both men were pronounced dead at the scene, police told the Hartford Courant. The quarry, which was closed to the public, had not been used since the 1980s, Farmington’s town manager told the newspaper.

Mark Price is survived by a 3-year-old daughter whom he “absolutely adored,” Siracusa said.

“He was an excellent father,” he said. “From day one, he was showing pictures, just so proud of her. He had a very tender heart.”

The fatal fall was especially tragic because Steven Price had recently received a clean bill of health after losing at least 50 pounds during cancer treatment, Siracusa said.

“Yesterday was very sullen, a lot of tears,” he said. “People are shocked. It’s a hard thing to wrap your mind around. You talk to a guy one day before and now he’s gone. It’s surreal.”