Any conforming structure that is damaged or deteriorated by fire, tornado, windstorm or in any other manner may be reconstructed to its original character provided it is not reconstructed to make it in any way a nonconforming use. For the purpose of this Chapter a structure shall be considered as deteriorated when the Planning and Zoning Administrator determines that at least fifty (50%) percent of the main structural members have collapsed. The reconstruction shall begin within 30 days and shall be completed within one year. The 30 day provision may be extended by the Board of Zoning Appeals only where evidence is submitted that the owner is awaiting an insurance settlement or that construction can not begin because of a severe weather condition or that the damage was the result of a natural disaster experienced in the City that makes it difficult for the owner to obtain contractor assistance. In such a case the owner shall also have debris removed within thirty (30) days, except as provided above.