The Port Huron Fire Department was called out to a structure fire Monday morning along the the 23-hundred block of Minnie Street.  When crews arrived they found the fire in an upstairs bedroom of the home which was quickly extinguished.  Officials say the home was vacant and no injuries were noted, but the cause of the blaze is suspected to be arson.  Anyone with any information about the fire can call the CAPTURE hotline at 987-66-88.