SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D/A

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

W. R. GRACE & CO.

(Name of Issuer)

COMMON STOCK, PAR VALUE $0.01 PER SHARE

(Title of Class of Securities)

38388F108

(CUSIP Number)

James C. Melville

Kaplan, Strangis and Kaplan, P.A.

5500 Wells Fargo Center

90 South Seventh Street

Minneapolis, MN

(612) 375-1138

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

September 18, 2014

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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This Amendment No. 2 to Schedule 13D (this “Amendment”) relates to the Common Stock, par value $0.01 per share (the “Common Stock”), of W. R. Grace & Co., a Delaware corporation (the “Issuer” or the “Company”). This Amendment is being filed by each of the Reporting Persons to amend the Schedule 13D which was originally filed on February 11, 2014, and amended on August 8, 2014 (as amended, the “Schedule 13D”). Unless otherwise indicated, all capitalized terms used herein but not defined herein shall have the same meanings as set forth in the Schedule 13D.

This Amendment is being filed to amend Items 3 and 5 of the Schedule 13D as set forth below.

Item 3. Source and Amount of Funds or Other Consideration

Item 3 of the Schedule 13D is hereby amended and supplemented by the addition of the following:

On September 18, 2014 the transactions described in the Termination Agreement, including receipt of the Consideration by the Trust, closed. Accordingly, the Warrant Implementation Agreement has not been amended and the Trust may exercise its rights under the Warrant Implementation Agreement at any time prior to the expiration of the Warrant on February 3, 2015, as more fully described in the seventh and eighth paragraphs of Item 2.

Item 5. Interest in Securities of the Issuer

Item 5(a) of the Schedule 13D is hereby amended and supplemented by replacing the fourth and fifth sentences of the first paragraph thereof with the following:

Based on WRG’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2014, there were 74,829,105 shares of Common Stock issued and outstanding as of July 31, 2014. The 10,000,000 shares of Common Stock beneficially owned by the Trust represent approximately 11.79% of the outstanding shares of Common Stock, including, for purposes of this calculation, the 10,000,000 shares of Common Stock that WRG is irrevocably committed to issue to the Trust at an exercise price of $17.00 per share under the Warrant Agreement subject to the terms of the Warrant Implementation Agreement.

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SIGNATURES

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.

Dated: September 26, 2014