FBI Charlotte(GASTONIA, N.C.) — As the FBI and local authorities desperately search for a 6-year-old boy who went missing in a North Carolina park, investigators are using divers, helicopters, drones and the boy’s parents’ voices to try to find him.

Maddox Ritch, 6, who has autism and does not talk, went missing Saturday while at the Rankin Lake Park in Gastonia with his family, police said.

Maddox has blond hair and blue eyes, weighs 45 pounds and is 4 feet tall, police said. He was wearing black shorts, closed-toe sandals and an orange T-shirt that reads “I am the Man” at the time he went missing, according to police.

On Monday, authorities checked dozens of dumpsters and went to businesses near the park asking for surveillance video while police dogs re-searched areas, the Gastonia Police Department said.

Crews searched the park’s lake using sonar and divers Monday.

Helicopters and drones have also been used in the search, police said.

Authorities have also recorded messages from Maddox’s parents and are playing those messages in the woods of the park in the hopes that their voices will persuade him to come out if he’s there, FBI Special Agent Jason Kaplan said Monday.

Former FBI agent and ABC News contributor Brad Garrett said that the idea of broadcasting Maddox’s parents’ familiar voices makes perfect sense.

Children with special needs “tend to be extremely close to their parents,” Garrett told ABC News. “If you have a kid that can’t really communicate but his parents talk to him every day … I completely understand why they would do it.”

Garrett said the FBI likely recorded the phrases Maddox’s parents use with him most often.

But as authorities turned to the media for help this week to spread the word about Maddox’s disappearance, the boy’s family shared their thoughts in a statement.

“I want to thank everyone for showing up to search for Maddox and also thank everyone for their prayers. We are trying to help the police in any way possible. They are still asking the public to just wait and let the professionals handle the search,” Maddox’s father said in a statement Monday to WCCB in Charlotte.

At a news conference Monday, authorities said Maddox’s mother and father have asked for privacy, and their names have not been released.

Police urge anyone who was at Rankin Lake Park on Saturday to call the tip line at 704-869-1075.

“We have spoken to many people who were there, but we want to make sure we talk to them all,” Gastonia Police Chief Robert Helton said in the statement released by police Monday. “No piece of information is too small. Something you may think is insignificant could be helpful to our case.”

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