Story highlights Sheriff's deputies found the dead dogs piled up in a shed at a kennel

A senator's son and his wife were watching the animals when they died

The kennel owners were out of town; they say it was an accident

The sheriff casts doubt on their story, so does a veterinarian

Heat. There's been plenty of it to go around in Arizona these first days of summer -- literally and politically -- after the air conditioning went out at a dog kennel.

Sheriff's deputies found 20 dead dogs piled up in a shed on Friday at Green Acres Dog Boarding Facility in Gilbert. The public shock over their deaths led a U.S. senator to issue a public statement on Monday.

As fate would have it, Republican Sen. Jeff Flake's son, Austin, was minding the kennel, when the dogs died.

Green Acres is owned and operated by two of Flake's relatives, Jesse and Maleisa Hughes, the Maricopa County Sheriff's office said.

The couple was out of town, leaving Austin Flake to dogsit, when a dog apparently chewed through the electric wiring connected to the air conditioning, said Sheriff Joe Arpaio.

He called it an accident, but at the same time cast doubt on the kennel owners' account of how the dogs died.

Kennel owners: It was an accident

"It was a tragic accident," Hughes told CNN. "We are heartbroken, and we're devastated." She doesn't believe anyone could have predicted or stopped what happened.

The air conditioning unit kicked out in the middle of the night, Hughes said.

Austin Flake and his wife slept at the east end of the house, while the temperature climbed to seething heights in the kennel on the west end, Maleisa Hughes said.

The dogs sleep there at night in a large, cooled room, she said.

The two sides of the house have separate air conditioning units, so the Flakes couldn't feel the suffocating heat.

During the day in Gilbert, the mercury has blasted up to over 100 degrees F, easily making it hard to find relief, perhaps even after temperatures dip back down to under 80 at night.

By the time the Flakes discovered the dogs at 5:30 a.m., the temperature was over 100 degrees, Hughes said.

The gnawed wire was still sputtering off sparks.

"It could have burned down our whole house," Hughes said. "My whole house could have burned down and all my children could have died, and then it would have been a tragedy."

One of the dogs that perished was her own.

The Flakes turned a hose and ice on the overheated dogs to try to save them, the sheriff's office said. "But failed to call for emergency assistance before the dogs died."

Sheriff: Story "seems unreasonable"

Sheriff Arpaio said that his office is investigating and that parts of Hughes' story seems suspicious. "It seems unreasonable that dogs could be healthy at 11 p.m. at night and dead by 5:30 a.m. the next morning as the owners suggest," he said.

A veterinarian he conferred with has corroborated his doubts, Arpaio said.

Deputies arrived to find some of the dogs' owners at Green Acres. A couple cried and hugged, as deputies used a wheel barrow to cart off dogs' carcasses wrapped in cloth.

Pet owners told Arpaio that the Hughes misled them about the number of dogs kept at the kennel.

The Hughes have not been arrested or charged, CNN affiliate KPNX reported

Prodigal embarrassments

News of the pet deaths on his son's watch were followed by a statement from Sen. Flake.

"I can't imagine the devastating loss these families are experiencing. My heart goes out to the owners who lost their beloved pets," he said.

In June of last year, another son, Tanner Flake, reportedly published racial epithets, homophobic slurs and anti-Semitic remarks on Twitter and used them as user names in online games.