Carfentanil, a synthetic opioid 100 times more potent than fentanyl, has been seized on Long Island for the first time. 

A seven-month narcotics investigation just led to a seizure of the deadly drug, typically used to tranquilize large mammals, in Suffolk County. 

Warrants went out for four suspected carfentanil drug peddlers. Three pleaded not guilty, but one remains at large. 

A public health alert was issued on Long Island and in Central New York State, where carfentanil was first spotted.

On the street, carfentanil is referred to as "Super Mario." 

"The drug supply here on Long Island and across New York State is tainted with this extremely lethal drug," said Steve Chassman, executive director of the Long Island Council on Alcoholism & Drug Dependence. 

Turning "a disastrous decision in an almost assured deadly one"

There are fears for people experimenting with carfentanil or buying pills illicitly.

"That substance is going to contain at least in part either fentanyl or carfentanil. So they're turning certainly a disastrous decision into an almost assured deadly one," said Suffolk County District Attorney Raymond Tierney.  

Carole Trottere of Old Field mourns her son, who suffered an accidental fentanyl overdose and died. She's worries about carfentanil, the new drug on the block. 

"Who are the people that are somewhere in a lab making this stuff? It's money. It's all about money," Trottere said. "This is an entire generation of young people in their prime that we have lost." 

A fentanyl crisis rally will be held at Robert Moses State Park on Sunday.