Alejandro the Pomeranian did not survive his flight to Detroit, and Delta Air Lines is now trying to figure out what killed the dog, reports CNBC. The dog was in a cargo hold on a Phoenix-to-Newark flight that stopped in Detroit, where he was found dead. "We know pets are an important member of the family and we are focused on the well-being of all animals we transport," Delta said in a statement. "Delta is conducting a thorough review of the situation and have been working directly with Alejandro's family to support them however we can. As part of that review, we want to find out more about why this may have occurred to ensure it doesn't happen again." Delta transported almost 58,000 animals last year, and two of them died. (More Delta Air Lines stories.)