(CNN) — A dog being flown by Delta Air Lines from Phoenix to Newark, New Jersey, died during the trip Wednesday, according to a spokeswoman for the airline.

The owners, Michael Dellegrazie and his girlfriend, were traveling from Phoenix to New York and decided to put their 8-year-old Pomeranian, Alejandro, on a plane so they could pick the dog up at the Newark airport.

During the layover in Detroit, Alejandro was held in a cargo facility.

“There was a stop in Detroit at 6 a.m. Alejandro was checked on. He was alive. Then between 8 a.m. and 8:30 a.m. he was checked on again and he was dead,” said Dellegrazie’s attorney, Evan Oshan.

A Delta official said the dog was discovered with vomit and fluids in the cage.

“The family is very upset,” Oshan said. “This is essentially their family member who died. To say they are upset is a gross understatement.”

Delta released a statement saying it is “conducting a thorough review of the situation” and has been working with Alejandro’s owners to support them however possible.

“We know pets are an important member of the family and we are focused on the well-being of all animals we transport,” the statement said. “As part of that review, we want to find out more about why this may have occurred to ensure it doesn’t happen again.”

The airline also said it offered to have the dog’s body evaluated by a veterinarian.

Other airline-related dog incidents

Alejandro’s death comes after United Airlines had three animal-related incidents in the span of a week in March.

First, a French bulldog died on a Houston-to-New York flight after a United flight attendant told its owners to put the dog, in its carrier, in an overhead bin. United spokesman Jonathan Guerin said the passenger told the flight attendant there was a dog in the carrier, but the attendant “did not hear or understand her, and did not knowingly place the dog in the overhead bin.”

A day after that incident, a 10-year-old German shepherd named Irgo was flown to Japan when he was supposed to end up in Kansas. In Irgo’s place was a Great Dane that was supposed to be en route to Japan. The dog was reunited with his family two days later.

Later that week, a flight was diverted to Akron, Ohio, after the airline realized a pet was loaded onto the flight in error, airline spokeswoman Maggie Schmerin told CNN. The flight was going from Newark to St. Louis, but the pet was due to fly from New Jersey to Akron. United told CNN the unidentified animal was “safely delivered to its owner.”

The-CNN-Wire™ & © 2024 Cable News Network, Inc., a Time Warner Company. All rights reserved.

Join our Newsletter for the latest news right to your inbox