EXHIBIT 5.1


                         [BARNES & THORNBURG LETTERHEAD]




                                                                  March 31, 2003



Vectren Corporation
Vectren Utility Holdings, Inc.
Indiana Gas Company, Inc.
Southern Indiana Gas and Electric Company
20 N.W. Fourth Street
Evansville, IN 47708

Ladies and Gentlemen:

     You  have  requested  our  opinion  in  connection  with  the  Registration
Statement  on Form S-3 (the  "Registration  Statement")  of Vectren  Corporation
("Vectren"),  Vectren Utility  Holdings,  Inc. ("VUHI") and Indiana Gas Company,
Inc.  ("Indiana  Gas") and Southern  Indiana Gas and Electric  Company (each, an
"Indiana  Guarantor")  and  Vectren  Energy  Delivery of Ohio,  Inc.  (the "Ohio
Guarantor" and, together with the Indiana Guarantors,  the "Guarantors"),  filed
pursuant to the Securities Act of 1933, as amended ("Securities Act"),  relating
to the offer and sale by Vectren of up to  $150,000,000  of shares of its common
stock,  without  par value,  and  related  common  share  purchase  rights  (the
"Shares"),  and  the  offer  and  sale by  VUHI  of up to  $200,000,000  of debt
securities (the "Debt  Securities") and related joint and several  guarantees by
the Guarantors of the Debt Securities (the  "Guarantees")  to be issued and sold
under the  provisions  of the  Indenture  dated  October 19,  2001,  between the
Corporation  and the  Guarantors and U.S. Bank Trust  National  Association,  as
Trustee (the "Indenture"). We have examined such records, certificates and other
documents and have made such investigation of law as we have deemed necessary in
the circumstances.

     Based on that examination and investigation, it is our opinion that:

     (i) When the steps taken in the next paragraph have been taken,  the Shares
will be validly issued, fully paid and nonassessable.

     The steps to be taken which are referred to in the next preceding paragraph
are:

          1.  Necessary  corporate  action on the part of the  Company  has been
     taken to authorize the issuance and sale of the Shares;

          2. The Shares are sold and delivered in accordance with the applicable
     underwriting  or  other  agreement  and  in  the  manner  described  in the
     Registration Statement (including all exhibits thereto); and

          3.  Compliance  with the  Securities  Act of  1933,  as  amended  (the
     "Securities Act") and applicable state blue sky laws.

     (ii) When the steps  mentioned in the next paragraph  have been taken,  and
the  Debt  Securities  and  the  Guarantees   shall  have  been  duly  executed,
authenticated  and delivered in  accordance  with the  Indenture,  and delivered
against payment therefor,  the Debt Securities will be legal,  valid and binding
obligations of VUHI and the Guarantees by the Indiana  Guarantors  will be legal
valid and binding  obligations of the respective Indiana Guarantors  enforceable
against each of them in accordance  with their  respective  terms subject to (a)
the  United  States   Bankruptcy  Code,   insolvency,   fraudulent   conveyance,
reorganization,  moratorium  and other  similar  laws now or hereafter in effect
relating  to our  affecting  creditors'  rights or  remedies  generally  and (b)
general  equitable  principles   (regardless  of  whether  such  enforcement  is
considered in a proceeding at law or in equity) and to judicial discretion.

     The steps to be taken which are referred to in the next preceding paragraph
are:

          1. Any  supplemental  Indenture to be entered into in connection  with
     the  issuance  of  the  Debt   Securities  and  Guarantees  has  been  duly
     authorized, executed and delivered by the Trustee, VUHI and the Guarantors;

          2. The specific terms of the particular Debt Securities have been duly
     authorized and established in accordance  with the applicable  supplemental
     Indenture;

          3. The Debt  Securities and the  Guarantees  have been issued and sold
     and the purchase price for the Debt  Securities and the Guarantees has been
     paid in  accordance  with the  transactions  proposed  in the  Registration
     Statement, as the same may be amended;

          4. Appropriate  definitive action by the Board of Directors of each of
     the Corporation and the Guarantors or an authorized  committee thereof with
     respect  to  the  proposed  transactions  set  forth  in  the  Registration
     Statement;

          5. VUHI and the  Guarantors  each shall have  received  all  necessary
     governmental  approvals  required  for the  issuance  and  sale of the Debt
     Securities and the Guarantees;

          6. Compliance with the Securities Act,  applicable state blue sky laws
     and the Trust Indenture Act of 1939, as amended; and

          7.  Issuance  and  sale  of the  Debt  Securities  and  Guarantees  in
     accordance with the corporate authorization aforesaid.

     This  opinion  letter is limited to the current  Federal laws of the United
States and the current  internal  laws of the State of Indiana  (without  giving
effect to any conflict of law  principles  thereof) and we have not  considered,
and express no opinion on, the laws of any other jurisdiction.

     We consent to the use of our name under the caption "Legal  Matters" in the
Prospectus  included  in the  Registration  Statement  and to the filing of this
opinion as Exhibit 5.1 to the Registration Statement.

                                            Very truly yours,


                                            /s/ Barnes & Thornburg

                                            BARNES & THORNBURG