EXHIBIT 16 March 26, 2002 Office of the Chief Accountant Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Dear Sir/Madam: We have read paragraphs one through four of Item 4 included in the Form 8-K dated March 22, 2002 of Vectren Corporation filed with the Securities and Exchange Commission and are in agreement with the statements contained therein. Very truly yours, Arthur Andersen LLP cc: Jerome A. Benkert, Jr. Executive Vice President, Chief Financial Officer and Treasurer Vectren Corporation