Bristol Community College's campus in New Bedford was evacuated Thursday.
Deputy Fire Chief Scott Kruger tells The Standard-Times that first responders received a call reporting the smell of natural gas at about 10 a.m., but once crews arrived it became apparent it wasn't natural gas, but some sort of chemical gas.
He says those taken to the hospital complained of trouble breathing. Others were treated at the scene.
The college in a tweet said 20 students and employees were treated.
A hazardous materials crew is trying to determine the source of the smell.
The college tweeted that campus will remain closed for the remainder of the day.
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