Hundreds flee chemical leak

(CNN) - A leak at a western Pennsylvania chemical plant Saturday formed a toxic cloud that affected more than 2,000 residents - some of whom fled their homes while others huddled indoors with windows shut, authorities said.

Three people were taken to hospitals but officials could not immediately say what ailed them.

Authorities located the source of the leak at the Indspec Chemical Corp. plant in Petrolia and shut it down. But it will take until mid-morning Sunday before officials greenlight residents to return home, said Freda Tarbell, spokeswoman for the Pennsylvania Department of Environmental Protection.

The number of injuries from the incident were not immediately available, though plant Manager Dave Dorko said all employees and inspectors at the plant were safe and accounted for.

Tarbell described the chemical as fuming sulfuric acid, which is also known as oleum.

The plant uses the chemical during its production process for its ability to absorb water, she said.