AMEREN ILLINOIS COMPANY

Incident Narrative

FINAL UPDATE 11/21/2018 - THE TOTAL DAMAGES IN PART D,2.D. ARE UPDATED TO SHOW BEST KNOWN PUBLIC DAMAGE ESTIMATES. SUPPLEMENTAL UPDATE 06/01/2017 - THE NUMBER OF INJURIES REQUIRING INPATIENT HOSPITALIZATION WAS UPDATED, INCLUDING A MEMBER OF THE PUBLIC AND AN AMEREN ILLINOIS CONTRACT LOCATOR. THE DOLLAR AMOUNT OF PUBLIC DAMAGES IS STILL THE BEST KNOWN ESTIMATE. SUPPLEMENTAL UPDATE 03/16/2017 - ESTIMATE OF $5MM PUBLIC DAMAGE ADDED. THIS IS UNSUBSTANTIATED ESTIMATE AND WILL BE UPDATED ONCE BETTER INFORMATION IS KNOWN. A THIRD PARTY CONTRACTOR WAS DIRECTIONAL BORING TO INSTALL TELECOMMUNICATION UTILITY FACILITIES AND HIT AN AMEREN ILLINOIS (AIC) GAS FACILITY. AIC RESPONDED TO THE HIT FACILITY AND HAD FOUR EMPLOYEES WORKING AT THE SCENE WHEN THE BUILDING AT 50 N 1ST AVENUE EXPLODED. ONE AIC EMPLOYEE WAS KILLED AND THREE WERE INJURED, TWO OF WHICH REQUIRED INPATIENT HOSPITALIZATION. ADDITIONAL CONTRIBUTING FACTORS TO THE INCIDENT ARE CURRENTLY UNDER INVESTIGATION BY THE NATIONAL TRANSPORTATION SAFETY BUREAU (NTSB). CLARIFICATION ON RESPONSES AS FOLLOWS: A.12 - THERE WERE NEWS REPORTS OF 12 INJURIES INCLUDING AIC EMPLOYEES. AT THIS TIME WE ARE ONLY AWARE OF THE INJURIES TO AIC EMPLOYEES REQUIRING INPATIENT HOSPITALIZATION, AND ARE NOTE AWARE IF OTHER INJURIES REQUIRED INPATIENT HOSPITALIZATION. A.16 - THE EAST SIDE OF THE SQUARE WAS EVACUATED BY EMERGENCY RESPONDERS AND THE TOTAL NUMBER OF INDIVIDUALS EVACUATED IS UNKNOWN AT THIS TIME. THE RESPONSE OF 50 IS AN UNSUBSTANTIATED ESTIMATE OF THE INDIVIDUALS IN AND AROUND THE SQUARE THAT WOULD HAVE BEEN EVACUATED. D.2.A. - THE EXTENT OF PUBLIC DAMAGES TO PROPERTY WILL MOST LIKELY BE IN THE MILLIONS OF DOLLARS. AT THIS TIME, AIC DOES NOT HAVE A VALID ESTIMATION OF THIS AMOUNT. G.13.A. - THIS DURATION REPRESENTS THE TIME THAT THE FIRST SYSTEM VALVES WERE CLOSED TO ISOLATE GAS MAINS TO THE TIME THE LAST GAS MAIN SEGMENT WAS REPRESSURIZED AND PUT BACK INTO SERVICE.