A suburban Atlanta man has been charged with felony murder and child cruelty after he left his 22-month-old son to die in an unattended hot car for seven hours on Wednesday, police said on Thursday.

Justin Ross Harris, 33, of Marietta, was supposed to drop his toddler, identified in reports as Cooper, at a daycare center around 9 a.m. Wednesday morning on his way to work, Reuters reported. But Harris drove straight to work, apparently forgetting that his son was strapped in his car seat in the back of the vehicle, Cobb County Police spokesman Dana Pierce said.

It wasn't until he was driving back home at 4 p.m., that he noticed Cooper's lifeless body in the back seat. Temperatures in the Atlanta area had reached 92 degrees F (33 C) on Wednesday, according to the National Weather Service.

Immediately pulling over the SUV at the Akers Mill Square shopping center on Cobb Parkway, Harris tried to perform CPR on Cooper.

A witness described watching the distraught father pull the child out of the car and attempt to resuscitate him, Dale Hamilton told CBS46 .

"He was constantly saying, 'What have I done, what have I done?'" Hamilton said.

The child was discovered by police as they were patrolling the area on Wednesday afternoon and saw a crowd gathered in a shopping center parking lot. Harris had to be restrained at the scene because he was so upset.

"As officers began to render medical treatment to the 22-month old male child, it was discovered that he was deceased after apparently being left unattended in his car seat inside the vehicle," a police statement said.

An autopsy will be conducted by the Cobb County Medical Examiner's Office to determine the cause of death for the child, police said. Harris is being held without bond in the Cobb County Jail, UK MailOnline reported.

"It's just a terrible, God-awful situation," Cobb County District Attorney Vic Reynolds told the Atlanta Journal-Constitution. "I can't imagine, I can't fathom what any parent would be going through at this stage. It's the type of case that affects the community."