Law enforcement personnel on Long Island conducted the largest fentanyl seizure in Nassau County history, officials said, taking enough drugs off the street to potentially have killed 150,000 people.

District Attorney Madeline Singas announced on Wednesday that, in coordination with task forces from the FBI and ATF, officials confiscated 400 grams of fentanyl — valued at more than $130,000. In addition to the massive amount of the deadly drug, 500 grams of cocaine worth $50,000 and eight guns were taken during the investigation into drug and gun rings centered around an apartment building on Terrace Avenue in Hempstead.

To get an idea how dangerous that quantity of fentanyl can be, just two milligrams of the substance is fatal to most adults, according to the Drug Enforcement Agency.

“The sheer quantity of deadly drugs seized by law enforcement amount to a weapon of mass destruction against our residents,” said County Executive Laura Curran. “Nassau County will continue cracking down on those dealing addiction and violence into our communities.”

The joint investigation from the agencies started back in April, but Singas said that on September 15 the alleged leader of the drug ring directed a partner to get a stash of heroin located at his girlfriend’s Hempstead apartment.

Ricky Jackson, an inmate at a Massachusetts prison, gave the order to Darren Devane to take possession of the 100 grams of the drug that was at Angelique White’s home, according to the indictment. Investigators from the Nassau County District Attorney’s office and members of the FBI Gang Taskforce on Long Island apprehended White and seized the heroin, then searched her apartment the next day and found another 300 grams of a white powdery substance.

According to officials, the 400 grams seized was not heroin, but actually was nearly pure fentanyl.

Devane had another supplier in addition to Jackson, according to the indictment, identified as Jamel Lewis. The 39-year-old Lewis allegedly used a network of dealers, including a man named Trevor Ford, to push narcotics around Hempstead. Devane is accused of storing some of the drugs with the help of another defendant — Michael Drew — who stashed the drugs at his mother’s apartment on Terrace Avenue, the indictment reads. Investigators on July 19 found 38 grams of crack cocaine at the residence after executing a search warrant.

Devane is also accused of telling his girlfriend, Shariah Usher, who was seven months pregnant at the time, to conduct a drug deal involving 100 grams of cocaine. The entire drug ring — including Devane, Jackson and Drew — are alleged members of the Bloods gang. The ring packaged and sold about $10,000 worth of cocaine every week, according to officials.

“People are dying every day because of the types of drugs these men are accused of selling in Nassau County,” said William Sweeney, the FBI New York Assistant Director-in-Charge. “We are facing a national crisis in part because dealers and pushers like those indicted in this investigation are all out to make a quick buck.”

All of the people mentioned in the drug deals were arraigned on multiple drug possession, selling and trafficking charges. Each of the defendants faces a maximum of 20 to 25 years in prison except for Lewis (who faces multiple potential sentences of at least 20 years) and Jackson, who could be sentenced to life in prison for operating as a major trafficker.

“Today’s announcement signals the end of a violent drug and gun ring operating in Hempstead that endangered thousands with the illegal narcotic fentanyl,” said John Devito, the special agent in charge for the New York Field Division of the ATF. “Thanks to the diligent efforts of the investigators on this case there is one less crew dealing in death on the streets of Long Island.”

While the drug investigation was ongoing, investigators were looking into a Brooklyn-based gun ring which led to the arrests of three people for allegedly trafficking and selling firearms in Hempstead.

On two occasions in April and June, Joseph Robertson is accused of traveling from Brooklyn to Hempstead to sell pistols, which were wrapped in T-shirts. Another man, Victor Cain, allegedly took an Uber from Brooklyn in May to Hempstead to sell a revolver. There is another defendant that has yet to be arraigned.

Among the guns seized were three .40-mm pistols, two .38-mm revolvers and a 30-round extended magazine. Robertson, 36, faces two counts each of weapons and firearm possession and four counts of sale of a firearm. Cain, 30, faces similar weapons and firearms charges.

Both Brooklyn residents are due back in court on December 5, and could face up to 15 years in prison.