SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13G/A

(RULE 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b),

(c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2

UNDER THE SECURITIES EXCHANGE ACT OF 1934 (“ACT”)

(AMENDMENT NO. 3)

First Financial Corporation

(Name of Issuer)

Common Stock

(Title of Class of Securities)

320218100

(CUSIP Number)

December 31, 2014

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

x Rule 13d-1(b)

¨ Rule 13d-1(c)

¨ Rule 13d-1(d)

ITEM 1(a) - NAME OF ISSUER:

First Financial Corporation

ITEM 1(b) - ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES:

One First Financial Plaza

Terre Haute, Indiana 47807

ITEM 2(a) - NAME OF PERSON FILING:

The PNC Financial Services Group, Inc.; PNC Bancorp, Inc.; PNC

Bank, National Association; and PNC Capital Advisors, LLC

ITEM 2(b) - ADDRESS OF PRINCIPAL BUSINESS OFFICE:

The PNC Financial Services Group, Inc. - One PNC Plaza, 249 Fifth Avenue, Pittsburgh, PA 15222-2707

PNC Bancorp, Inc. - 222 Delaware Avenue, Wilmington, DE 19801

PNC Bank, National Association - One PNC Plaza, 249 Fifth Avenue, Pittsburgh, PA 15222-2707

PNC Capital Advisors, LLC - One PNC Plaza, 249 Fifth Avenue, Pittsburgh, PA 15222-2707

ITEM 2(c) - CITIZENSHIP:

The PNC Financial Services Group, Inc. - Pennsylvania

PNC Bancorp, Inc. - Delaware

PNC Bank, National Association - United States

PNC Capital Advisors, LLC - Delaware

ITEM 2(d) - TITLE OF CLASS OF SECURITIES:

Common

ITEM 2(e) - CUSIP NUMBER:

320218100

ITEM 3 - IF THIS STATEMENT IS FILED PURSUANT TO RULE 13d-1(b), OR 13d-2(b), CHECK WHETHER THE PERSON FILING IS A:

ITEM 4 - OWNERSHIP:

The following information is as of December 31, 2014:

Of the total shares of common stock reported herein, 993,276 shares are held in accounts at PNC Bank, National Association (“PNC Bank”) in a fiduciary capacity for clients. PNC Bank is the co-trustee on a particular trust account (T. Rigasco Trust) holding at year end 900,458 of the shares of the common stock reported herein (6.98% of the class). Also, PNC Bank is the co-trustee on another trust account holding at year end 92,772 of the shares of the common stock reported herein. Along with PNC Bank, Mitchell E. Daniels, Jr. is co-trustee for these trusts. The co-trustees may be deemed to share voting authority and dispositive power with respect to the shares of common stock of the issuer held in these trust accounts.

Of the total shares of common stock reported herein, 47 shares are held in accounts at PNC Capital Advisors, LLC in a fiduciary capacity for clients.

The inclusion of the reporting persons and such securities in this report shall not be deemed an admission of beneficial ownership by the reporting persons for the purposes of Section 13(d) or 13(g) of the Act, or for any other purposes.

ITEM 5 - OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS:

Not Applicable.

ITEM 6 - OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON:

PNC Bank and Mitchell E. Daniels, Jr., as co-trustees, share the power to direct the receipt of dividends from, or the proceeds from the sale of, the common stock held by the trusts noted in Item 4 above. The beneficiaries of one of the trusts have the right to receive dividends from the common stock in their trust account.

PNC Capital Advisors, LLC has the power to direct the receipt of dividends from, or the proceeds from the sale of, the common stock of the issuer held by the mutual fund.

ITEM 7 - IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY:

Included are the following subsidiaries of The PNC Financial Services Group, Inc. - HC:

PNC Bancorp, Inc. - HC (wholly owned subsidiary of The PNC Financial Services Group, Inc.)

PNC Bank, National Association - BK (wholly owned subsidiary of PNC Bancorp, Inc.)

PNC Capital Advisors, LLC - IA (wholly owned subsidiary of PNC Bank, National Association)

ITEM 8 - IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:

Not Applicable.

ITEM 9 - NOTICE OF DISSOLUTION OF GROUP:

Not Applicable.

ITEM 10 - CERTIFICATION:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

AN AGREEMENT TO FILE A JOINT STATEMENT WAS PREVIOUSLY FILED