A scooter-riding suspect trying to flee a Bronx drug bust died when an undercover NYPD sergeant threw a cooler at him – prompting the department to suspend the cop and warn its rank-and-file about possible “unrest” Thursday, police sources said.

The sergeant, identified by the NYPD as Erik Duran, was conducting a buy-and-bust operation on Aqueduct Avenue near West 190th Street in Kingsbridge Heights around 5:30 p.m. Wednesday when the suspect, believed to be in his 20s, took off, the sources said. 

Duran allegedly chucked what’s believed to be a plastic cooler at the fleeing man — causing him to lose control of his scooter, strike a parked car and fall to the ground, according to the sources.

He suffered body trauma and was pronounced dead by EMS workers at the site of the crash.

Duran was suspended Thursday, the NYPD said in a statement. 

“Early today, New York City Police Department Sergeant Erik Duran was suspended from duty without pay following a fatal incident in the Bronx on Wednesday afternoon involving a man attempting to flee from the police on a motorcycle,” the department said in an official statement. 

“The city’s medical examiner will determine the cause of death.”

An alert that went out internally to those in the department, and was obtained by The Post, warned officers that the incident could spark a strong public reaction. 

“We had an incident in the Bronx with narcotics that is high potential for unrest,” the memo said. 

The notice advised officers to reminded officers to keep their helmets and batons in their police cruiser and to set up barricades, especially at historic locations.

State Attorney General Letitia James’ office was leading the investigation into the fatal encounter, with the help of the NYPD’s Force Investigation Division, the department said in its statement.

“The NYPD is committed to ensuring that there will be a full, thorough, and transparent investigation of this incident to determine the facts and to take the appropriate steps forward,” the statement said.