Reports of an active shooter with a shotgun at Bronxville’s Lawrence Hospital sparked a massive police response in Westchester County on Sunday night, which ended with no evidence of shots fired and no shooter found, according to sources.

Heavily armed SWAT teams are doing a room by room search of the medical facility to try and locate the possible suspect, who was reported to be on the 6th floor. But sources told The Post that there was no evidence of a gunman.

Westchester County cops had been assisting Bronxville PD in the search. Authorities said they were working to evacuate whoever couldn’t physically leave the hospital.

Authorities said they were working to evacuate whoever could physically leave the hospital.

An employee told The Journal News that people in the hospital weren’t taking the response “serious.”

“I heard a code silver on the loudspeaker and I just ran out,” said worker Mcaaulay Mike. “I got out of there, nobody seemed to really take it serious, but I got out of there.”

A woman who identified herself as Mary was in the emergency room waiting area when hospital personnel began asking people to leave.

“The police came in, they were very discreet,” she told The Post. “They had guns, they had their equipment on. Very calm.”

Cops were still on the scene as of 10:30 p.m.

The hospital tweeted: “We are continuing to gather details about tonight’s developments and will provide an update when we can. Please do not come to the hospital tonight unless it is an emergency. Thank you for your thoughts and prayers for our staff, patients and law enforcement.”