It was a terrifying evening on Monday at Yale-New Haven Hospital.

According to nbcconnecticut.com, at around 10 p.m. on Monday evening a man walked into the hospital with a backpack and demanded to talk with a supervisor.

Before anyone could do anything, he whipped out a towel from his backpack while shouting, "chemical warfare" while launching the towel on a nearby desk. Before the police arrived, the man had raced out of the hospital.

The New Haven Fire Department Chief had the towel tested for hazardous substances but found nothing. They are completing secondary testing just to be sure.

Three people who were closest to the towel have been decontaminated for potential exposure just to be safe. So far no one has shown any symptoms of contamination. New Haven Police are still trying to track the man down.