Fire crews battle 400-acre wildfire in Fresno County

SAN JOAQUIN, Calif. - Cal Fire is responding to a wildfire on South Colusa and West Floral Avenues in San Joaquin Sunday afternoon, according to their social media posts. 

The fire has grown to 400 acres and is 50% contained. Officials said the cause of the fire is under investigation. 

The fire reportedly started around 11:30 a.m., officials said.

There is a threat to structures and powerlines, according to officials. 

This story is developing and will be updated with more information.