Transcript for Family says dog died on delayed flight stuck on tarmac
We'll turn to a family searching for answers after their dog died in a cargo hold of a united airlines plane when their flight was delayed on the tarmac for two Hou. Jim Avila has the story. Reporter: Lulu was part of the family, five years old, a cavalier king Charles spaniel. Her owners say their vet signed off on her health so she was loaded into the cargo section of a united flight from Houston to San Francisco. The flight was delayed on the ground in Houston for two hours according to lulu's family Facebook post which reports when we went to pick her up, she was dead. United has a special animal cargo policy and facilities called pet safe that include air conditioned climate controlled holds in the air on board transport vehicles and warehouses on the ground. Their website assures pet owners of comfort in any weather conditions and that pets will be the last ones loaded and the first ones off the plane's cargo area. Still, according to the department of transportation's statistics, from 2014 through 2016, of the 26 pet deaths during transport, united had nine, more than any other U.S. Carrier. The humane society warns that cargo hold travel should always be a last resort and in the summer, middle of the day flights should be avoided and some dogs should not fly at all. Unfortunately, for lulu and her family, lulu had a -- what we call smooshed in face which made her more susceptible to the extreme heat conditions. Reporter: The airline says in a statement they are so sorry to learn of lulu's passing. They've offered condolences and assistance to the family and promise a thorough review of the incident. Another tip from the humane society if you must bring your dog along and it's too big to fit under the seat, personally tell the pilot or co-pilot that the dog is there or a flight attendant because they can then watch out and be extra vigilant about whether or not it's too hot in the cargo area. George. That does make sense. Jim, thanks very much.
This transcript has been automatically generated and may not be 100% accurate.