As used in this article, the following terms shall have the meanings indicated:
An unforeseen occurrence or condition calling for immediate action; a crisis or a time of difficulty or danger, including but not limited to a natural disaster or man-made calamity including flood, conflagration, tornado, earthquake, or explosion, or extreme weather conditions within the limits of the Borough, resulting in the actual or potential death or injury of persons and/or the destruction of property to such an extent that extraordinary measures must be taken to protect the public health, safety, and welfare; an event or any condition of or use of premises which is detrimental to the property or safety of others and which causes or tends to cause substantial opportunity for danger to persons or other property.