A medical scare broke out at a hotel in the East Bay Area Saturday evening.
At least five ambulances were called to the scene of the Walnut Creek Holiday Inn Express on Main Street, where at least 10 people reported having serious breathing issues, fire officials said.
Hotel guests complained of a "pepper spray-like" smell, and said they suffered from itchy eyes and throats. The hotel has been evacuated.
Five people were treated at the scene, while one person was transported to a nearby hospital with non life-threatening injuries.
Two Hazmat teams combed the hotel looking for what the issue could be, but were unable to locate the source of the irritant by about 10:30 p.m.
The structure was ventilated and the HVAC system was switched to bring in a lot of fresh air, a hotel worker said.
Firefighters on on scene investigating whether the cause is a harmful substance.