A 45-year-old man was shot to death after ambushing an armed Hudson Valley hospital security guard with a knife in the emergency room lobby, authorities say.

Police in Newburgh say they were called to Montefiore St. Luke’s Cornwall Hospital late Thursday for a report of a gun going off.

According to their investigation, the man, identified as Carlos Ortiz, was behaving in a disorderly manner in the room lobby and had pulled the fire alarm. Hospital security staff confronted him, and that’s when police say he pulled out the knife and attacked one of the guards. The guard fired a single round at Ortiz.

Ortiz, who lived in the city of Newburgh, was later pronounced dead. It wasn’t clear if he was known to the hospital prior to Thursday night.

A woman who had been near the scene also was hurt, with what authorities say appears to be a non-life-threatening injury.

No charges have been filed at this time. The incident remains under investigation.

Anyone with information is asked to call 845-569-7519.