NEW YORK (CBSNewYork) — A Staten Island man is determined to find out why his dog — traveling alone on a Delta Air Lines flight — never made it home.

The animal suddenly died in Detroit, and now he wants to know what happened.

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Michael Dellagrazie told CBS2’s Hazel Sanchez on Sunday he isn’t satisfied with Delta’s response after his dog, Alejandro, was found dead during a layover in the Motor City, while in the airline’s care.

“We lost a family member. That’s exactly what happened, and someone has to be responsible for it,” Dellegrazie said.

Dellagrazie said his 8-year-old Pomeranian was flying without his owners on an overnight Delta flight from Phoenix to Newark. The airline said Alejandro was alive when the plane landed at Detroit Metropolitan Airport on Thursday morning, but when it was time to load him onto his connecting flight, he was unresponsive.

“He was alive at 6:30 a.m., and then at 8:20 he wasn’t moving. And it just doesn’t make any sense to me,” Dellagrazie said.

Delta said it launched an immediate investigation and “…offered to have Alejandro evaluated by a veterinarian … to find out more about why this may have occurred.”

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But the family chose to arrange the necropsy on their own. Dellagrazie and his attorney, Evan Oshan, flew to Detroit two days later to retrieve the dog from Delta’s cargo area.

“We just want to get him home,” Dellagrazie said.

Delta released Alejandro in a crate with his belongings and bloodstained blanket, prompting a call to police.

“I want to know what happened here? What happened here? Why is there blood on this blanket?” Dellagrazie said.

While Dellagrazie waits to find out what killed Alejandro after the Delta flight, he said the bottom line is his dog “was in their care, and they didn’t take care of him.”

There have been at least four dog deaths while in the care of U.S. airlines this year. In 2017, there were 24 deaths out of the more than half million pets transported.

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