ATLANTA -- Parents are speaking out after losing their children to drugs just 3 weeks ago. They're warning everyone about "Gray Death" - illegal pills and powders "amped up" with new versions of fentanyl.

"With the stuff that's out there, the smallest amount - one mistake - will end lives," said one of the fathers, Greg Manning. "These kids have no idea what is being put in whatever recreational drug they're trying.... And our message is, let's teach these kids what's out there."

The Gray Death concoctions are so powerful they can kill with a single touch or breath. And the Georgia Bureau of Investigation is worried these drugs are spreading unchecked.

"Our hearts are completely shattered and broken right now," Kathi Abraham said.

Kathi and David Abraham, and Lisa and Greg Manning, spoke of how they want to help others, as they grieve the loss of their sons, 19-year-old Joseph Abraham and 18-year-old Dustin Manning.

On May 26, sometime before dawn - in their homes less than half a mile apart in Gwinnett County - their sons died of apparent accidental drug overdoses. Next to Dustin police found a small, off-white or gray pill wrapped in paper.

Detectives suspected the drugs the two teens ingested were "laced with something fatal."

Were the drugs laced with fentanyl - the "Gray Death" - that is spreading fast across Georgia now?

"Whatever it is, it's deadly," David Abraham said.

The Abrahams and the Mannings had been helping lead their sons out of addiction.

"Dustin fought this disease for years," Lisa Manning said, her eyes filling with tears.

"It's three steps forward, two steps back," David said.

So when their sons relapsed a final time, the parents suspected the teens might have ingested one of the new "Gray Death" fentanyl hybrids now on the streets, and their sons never realized the drugs could be fatal.

"And the smallest amount will end their lives," Greg Manning said.

"This fentanyl, you make a mistake, you're dead," David added. "There's no second chances."

GBI Director Vernon Keenan said the new drug variants are "serious business."

"Fentanyl will kill you graveyard dead," Keenan said last week.

The Gray Death drugs have killed at least six people in Georgia so far this year and hospitalized dozens more.

"And I loved her," one grieving widower in middle Georgia said of his wife last week, who, police said, had died from taking an off-the-street, illegal version of Percoset containing fentanyl. "I still love her, but she gone."

The death toll is expected to rise. At the GBI's labs in DeKalb County, up to 75 additional, fentanyl "Gray Death" investigations are underway so far.

"There is no over-dramatization that's going on here," GBI Chemistry Section Manager Deneen Kilcrease said.

Kilcrease and her team are looking for the tiniest amounts of illegal, fentanyl hybrids in samples that local police sent them.

"There's nothing that's been as deadly in such small doses as this," Kilcrease said.

Tiny, murderous monsters no bigger than grains of salt: all mixed into fake Percoset pills or heroin or pot - those are some of the most common instances of Gray Death.

It's so powerful that police are now treating all overdose investigations as if they are Gray Death cases - which includes wearing masks and gloves and other protective gear - because the drug can be absorbed through the skin by touching it, or transmitted invisibly in the air. It kills its victims fast - before they get high.

"Just a couple of flakes is all it takes," GBI spokesperson Nelly Miles said. "Fentanyl just by itself is 50 to 100 times more potent than even heroin. But a combination of them, the potency levels are astronomical."

She added that this is something that's never been seen in Georgia.

In 2015, 1,302 drug overdose deaths, overall, were reported in Georgia - an average of at least three fatal overdoses a day. That's more than twice the number of homicides - 498 - by people using guns in Georgia that year.

The Abrahams and the Mannings are waiting to find out from the Medical Examiner whether fentanyl contributed to their sons' deaths. Regardless, they will continue to work on their new mission - drug education and awareness to save lives.

"We have a captive audience in our schools," Greg Manning said. "Use that opportunity to teach them [in the schools and churches and at home] what's going on out there. We need to be responsive to what's happening in our community."

"My feeling is, the high schools - it's too late," Lisa Manning said. "Even middle school, it's too late. These kids are doing drugs at 12 and 13 years old and being exposed to it even at an earlier age. We need to start it for prevention in the elementary schools - third, fourth, fifth graders need to be exposed to the education about it."

And they are starting to raise money for families needing addiction rehab and counseling.

"We don't want our boys' lives to be for nothing," Kathi Abraham said. You know, they were great kids, well-liked, great hearts.... We're determined to get the word out there.... somehow work on reaching them early. You know, we can't save our own boys, now. And God knows we tried, But, I mean, we hope that we can impact some other lives."

All while this wildfire of Gray Death burns across the state.

"We want to keep in this," David said. "And if this somehow saves one kid's life, boy it was worth it, wasn't it?"