HOUSTON -

When traveling, many things can go wrong.

For U.S. Air Force veteran Jason Box, his wife Crystal and their four children, it all began last April 17 when they decided to send little Booboo, their 12-pound chihuahua-jack terrier-mix, aboard United Airlines from their home in Guam to what would be their new home in Boston.

The more than 20-hour flight was supposed to be simple. It was arranged through United's PetSafe program.

It was supposed to begin with Booboo being housed in a small pet kennel. Then for $500, she would be flown from Guam to Hawaii. There Booboo would have an overnight stay, including food, water and a walk. After that, she would fly to Houston with another scheduled stop for food, water and a walk. The final leg of the trip would take Booboo from Houston to Boston the following day.

However, about 24 hours into the trip, Crystal Box said she got the startling news that Booboo, who was supposed to be in Hawaii, was already in Houston, way ahead of schedule. Crystal was furious.

"When we found out that Booboo was in Houston, that told me that our baby was left locked-up in a box for about 24 hours with no food, no water, no care whatsoever," Crystal said.

Two hours later the news got worse. The Box's were notified that Booboo had broken free from her handler in Houston and had been missing for four hours.

That made the Box family even more upset because two hours earlier, United representatives had told Crystal that Booboo was within their sight and was doing great.

Eight hours after later United called the Box's again, and this time to tell the family that their little Booboo had been hit by a speeding car and was killed instantly.

"That just killed me completely because she was my little girl," said Crystal.  "It was like being told that one of my children had been killed. I was devastated."

Making the loss even worse was the fact that Booboo had originally been the Box's 11-year-old daughter, Terijean's, therapy dog.

Terijean had been traumatized by watching her older brother be killed in an auto accident. Now Booboo had died the same way.

That was three months ago, and today, Crystal and Jason Box are still fighting to get their dog's body back.

They also want an official autopsy report on the dog's death and the name and phone number of the veterinarian that pronounced Booboo dead.

We contacted United Airlines asking for an interview so we could ask questions about this tragedy.

United issued this statement saying, "United Airlines is committed to ensuring the safe travel of all of the pets that fly with us, and we regret the loss of Booboo. We have been in close contact with the Box family about their beloved dog, and we will continue to work with them to compensate them for their loss".

As a result of this tragedy, United Airlines has already started using double leashes at all of their PetSafe kennels to prevent future problems.