Arizona law enforcement officials are investigating the deaths of up to 20 dogs that were under the care of a senator's son outside Phoenix, Arizona, MyFoxPhoenix.com reports.

The Maricopa County Sheriff’s Office said it appears the dogs at the Green Acre boarding house died of heat exhaustion in a “tragic accident” after one of the dogs apparently chewed through a power cord, knocking out an air-conditioning unit.

The son and daughter-in-law of Sen. Jeff Flake, R-Ariz., were in charge of caring for the dogs while the house's owners were out of town, MyFoxPhoenix.com reported.

"I learned of this tragic accident over the weekend. I can't imagine the devastating loss these families are experiencing," Flake said in a statement. "My heart goes out to the owners who lost their beloved pets."

Workers at the Green Acre boarding house near Gilbert found the dogs at 5:30 a.m. Friday. The dogs were last checked about 11 p.m. Thursday.

Upset dog owners told MyFox Phoenix they did not learn of the tragedy until Saturday morning. Valerie Collins left two dogs in the care of the facility.

“I demanded. I got in the owner's face,” she told the station. “We went out of the front and he carried my Daisy, who was lifeless. I prayed that they were still alive and he just threw her at my feet like a piece of meat.”

Owners Todd and MaLeisa Hughes were in Florida at the time of the accident.

The Arizona Republic said the owners were “heartbroken” over the tragedy and that it claimed one of their dogs.

"The wire was sparking. It could have burned down our whole house," MaLeisa Hughes told the newspaper. "My whole house could have burned down and all my children could have died, and then it would have been a tragedy. But because it didn't catch fire, we're dog killers."

Fox News' Kara Rowland contributed to this report.

Click here to read more from MyFoxPhoenix.com and the Arizona Republic.