If, at any time commencing on the date which is twelve (12) months prior to the Initial Expiration Date or any Expiration Date for a Renewal Term, 50% or more of the square feet of the Improvements are so damaged or destroyed by fire or other casualty that they are rendered substantially untenantable, Lessee shall have the right, upon ten (10) Business Days’ prior written notice to Lessor, to terminate this Lease. Upon the date which is ten (10) Business Days following Lessor’s receipt of such notice, this Lease shall be deemed terminated and of no further force and effect and all insurance proceeds in connection with such casualty, shall be paid to, and retained by, Lessor free and clear of any claim by or through Lessee.