About 100 people inside Northgate Mall were exposed to pepper spray and had to be brought outside because of coughing and eye irritation Wednesday morning. The Seattle Fire Department responded about 10:30 a.m. to the mall where scores of people were standing outside and complaining about eye irritation and coughing. Police concluded that pepper spray -- or a pepper spray-like substance -- was sprayed around the middle of the mall, but it then spread to a few stores nearby. None of the 100 people who exhibited symptoms were taken to a hospital, according to the fire department. Firefighters worked with the building engineers to make sure the substance was cleared from the mall's HVAC system. It's unclear how the pepper spray incident happened, whether it was malicious or whether police are looking for a suspect. People were allowed back into the mall about an hour after the incident.