Vegetation fire in Clayton grows to more than 40 acres

The Norton Fire in Clayton. Image from CAL FIRE. 

A vegetation fire in Clayton has grown to more than 40 acres, officials say. 

The Norton Fire broke out on Thursday at Nortonville Road and Diamond Way in Contra Costa County, officials with CAL FIRE said. They first posted about the fire on social media at 5:39 p.m. 

"Firefighters are working diligently to contain the fire currently burning in the grass. Significant air and ground resources are at scene and en route," CAL FIRE's SCU unit said. 

The Contra Costa County Fire Department is also working this incident.

It is not clear how the fire began. No structures appear to be threatened. The cause of the fire is under investigation. 

This is a developing story. 

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