A fire which had its inception at 5 a.m. today gutted the beer hall of the Carbon County Fairgrounds in Lehighton. Owned by the Carbon County Fair Association, the large frame structure was a familiar landmark to fair attendants, being located a short distance to the right of the main gate on Mahoning Street. Corvin Solt, fire chief, said flames were already shooting through the roof when the firemen arrived in response to the early morning alarm. The cause of the fire wasn't determined.