SECURITIES AND EXCHANGE COMMISSION

                              WASHINGTON, DC 20549

                                    FORM 8-K

                                 CURRENT REPORT


     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934


      Date of Report (Date of earliest event reported) - December 31, 1997


                                 HSB GROUP, INC.
             (Exact name of registrant as specified in its charter)


     Connecticut                   001-13135             06-1475343
   (State or other               (Commission           (IRS Employer
jurisdiction of incorporation)    File Number)       Identification No.)


               One State Street, Hartford, Connecticut 06102-5024
               (Address of principal executive offices) (Zip Code)


      Registrant's telephone number, including area code - (860-722-1866)






Item 5. Other Events.

On January 6, 1998 The Hartford Steam Boiler  Inspection  and Insurance  Company
("HSB"),  the principal  subsidiary of HSB Group,  Inc. (the "Company") sold its
interest  in  Industrial   Risk  Insurers   ("IRI")  to  Employers   Reinsurance
Corporation  in  accordance  with  a  previously  announced  purchase  and  sale
agreement  between  ERC  and  IRI's  twenty-three  member  insurers.  IRI  is an
unincorporated   joint  underwriting   association  which  underwrites  property
insurance  on  highly   protected   risks.   HSB  received   gross  proceeds  of
approximately  $50 million,  prior to transaction  costs, for its 23.5% share in
IRI.  Because the sale was  structured in part as a reinsurance  transaction,  a
portion of HSB's gain will be deferred and recognized over the remaining term of
IRI's in-force business as of the date of the closing of the sale.

Contemporaneous with the close of the sale, IRI was reconstituted with ERC (with
a 99.5%  share ) and HSB (with a .5%  share)  as its sole  members.  Michael  L.
Downs,  senior vice president of the Company and HSB, will be appointed chairman
and  chief  executive  officer  of the  reconstituted  IRI.  HSB will  write the
business for the reconstituted IRI using its insurance licenses and will provide
certain other  services.  It is anticipated  that HSB will transfer its domestic
highly protected risk  manufacturing book of business to IRI and will retain 85%
of the  equipment  breakdown  business and 15% of the  property  business of the
combined insurance portfolio.

In a related transaction,  a Delaware business trust newly formed by the Company
has sold $300 million of 7% Convertible Capital Securities ("Convertible Capital
Securities")  to ERC.  The  proceeds  from the sale  were  used by the  trust to
purchase  7%  Convertible   Subordinated  Deferrable  Interest  Debentures  (the
"Debentures")  from the  Company  pursuant  to the terms of an  Indenture  dated
December  31,1997,  issued by the Company to the First National Bank of Chicago,
as Trustee,  (the  "Indenture")  a copy of which is attached as Exhibit 4.2. The
Company  contributed  $250 million of the proceeds it received  upon the sale of
its Debentures to HSB to support the anticipated increase in its direct writings
attributable to the IRI business.






The following  represents a pro forma condensed  balance sheet of the Company at
September 30, 1997 assuming the Convertible  Capital  Securities had been issued
as of September 30, 1997.

                           (in millions except ratios)

                                                    Actual           ProForma
                                                   9/30/97            9/30/97
                                                   -------           --------
Cash & Invested Assets                              $713.3           $1,013.3
Insurance Premiums Receivable                        126.8              126.8
Prepaid Acquisition Costs                             45.5               45.5
Reinsurance Assets                                   146.4              146.4
Investment in Radian                                  85.0               85.0
Other                                                139.7              139.7

                                             ==============     ==============
  Total Assets                                    $1,256.7           $1,556.7
                                             ==============     ==============

Unearned Insurance Premiums                         $295.8             $295.8
Claims & Adjustment Expenses                         278.8              278.8
Debt                                                  43.1               43.1
Other Liabilities                                    189.6              189.6

                                             --------------     --------------
  Total Liabilities                                  807.3              807.3
                                             --------------     --------------

Convertible Redeemable Preferred Stock                20.0                    *
HSB Capital Securities I                             108.9              108.9
HSB Capital Securities II                                               300.0
Shareholders' Equity                                 320.5              340.5

                                             ==============     ==============
Total                                             $1,256.7           $1,556.7
                                             ==============     ==============


*The pro forma condensed balance sheet includes adjustments for (i) the issuance
of $300  million of  Convertible  Capital  Securities;  and (ii) the issuance of
398,406  shares of common  stock on  October  30,  1997 upon  conversion  of the
convertible redeemable preferred stock.







The following represents a pro forma ratio of earnings to fixed charges assuming
the Convertible Capital Securities had been issued as of January 1, 1997.

                                  Actual                  ProForma
                                  1/1/97                  1/1/97
                                  ------                  ---------
Ratio of Earnings to
Fixed Charges                        5.27                    2.42 *





* If pro forma data were adjusted to reflect the potential  investment  earnings
at a 7% rate on the proceeds  from the sale of the $300  million of  Convertible
Capital Securities, the ratio would be approximately 2.96%.


The Convertible Capital Securities are callable by the Company at its option (i)
at any time  after  seven  years;  (ii)  upon the  occurrence  of a tax event as
defined  in the  Indenture;  (iii)  in the  event  that  the  Company  vetoes  a
prospective  purchaser of the  Convertible  Capital  Securities;  or (iv) in the
event of a change in control of ERC.  The  Convertible  Capital  Securities  are
mandatorily  redeemable on December 31, 2017,  and are  redeemable at par plus a
redemption premium, at the option of ERC, in the event of a change in control of
the Company within five years following issuance of the securities.

The  Convertible  Capital  Securities are  convertible,  in whole or in part, at
ERC's option at any time, subject to regulatory approval, into shares of Company
common stock at a conversion  price of $85,  subject to adjustment.  The Company
has provided  certain  registration  rights to ERC in connection with the common
stock into which the Convertible Capital Securities are convertible  pursuant to
a  Registration  Rights  Agreement  dated  December 31, 1997, a copy of which is
attached as Exhibit 4.8.

The  foregoing  summary of the terms of the  Convertible  Capital  Securities is
qualified by reference to the Trust  Agreement dated December 31, 1997 among the
Company, the First National Bank of Chicago, as Property Trustee,  First Chicago
Delaware  Inc.,  as  Delaware  Trustee  and the  Administrative  Trustees  named
therein, a copy of which is attached as Exhibit 4.5.

Were ERC to exercise its conversion  rights in total,  it would hold, on a fully
diluted basis,  approximately  15.3% of the Company's common stock.  Pursuant to
certain  provisions  contained in the Purchase Agreement dated December 31, 1997
attached as Exhibit  4.1,  ERC has agreed to certain  "standstill"  arrangements
which for a period of five years will  preclude ERC from  purchasing  any common
stock of the Company,  other than by exercise of its conversion rights, and will
limit its ability to take  certain  other  actions  with  respect to the Company
during that period.






Item 7(c)  Exhibits.

Exhibit

4.1      Purchase  Agreement  dated as of  December  31,  1997  among  Employers
         Reinsurance  Corporation,  ERC  Life  Reinsurance  Corporation  and HSB
         Group, Inc.

4.2      Indenture of HSB Group, Inc. relating to the 7.0% Convertible 
         Subordinated Deferrable Interest Debenture Due December 31, 2017

4.3      Form of Certificate of 7.0% Convertible Subordinated Deferrable 
         Interest Debentures due December 31, 2017

4.4      Certificate of Trust of HSB Capital II

4.5      Trust Agreement dated as of December 31, 1997 among HSB Group,
         Inc., The First National Bank of Chicago, First Chicago Delaware Inc.
         and The Administrative Trustees named therein.

4.6      Form of Capital Securities Certificate of HSB Capital II

4.7      Guarantee Agreement between HSB Group, Inc. and The First
         National Bank of Chicago dated as of December 31, 1997 relating
         to HSB Capital II.

4.8      Registration  Rights  Agreement  dated as of  December  31,  1997 among
         Employers Reinsurance Corporation, ERC Life Reinsurance Corporation and
         HSB Group, Inc.













     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
     Registrant  has duly  caused  this report to be signed on its behalf by the
     undersigned, thereunto duly authorized.


                                 HSB GROUP, INC.



     Dated:  January 12, 1998     /s/ Saul L. Basch
                                  Saul L. Basch
                                  Senior Vice President, Treasurer and
                                  Chief Financial Officer





                                  EXHIBIT INDEX

Exhibit

4.1      Purchase  Agreement  dated as of  December  31,  1997  among  Employers
         Reinsurance  Corporation,  ERC  Life  Reinsurance  Corporation  and HSB
         Group, Inc.

4.2      Indenture of HSB Group, Inc. relating to the 7.0% Convertible  
         Subordinated Deferrable Interest Debenture Due December 31, 2017

4.3      Form of Certificate of 7.0% Convertible Subordinated Deferrable 
         Interest Debentures due December 31, 2017

4.4      Certificate of Trust of HSB Capital II

4.5      Trust Agreement dated as of December 31, 1997 among HSB Group,
         Inc., The First National Bank of Chicago, First Chicago Delaware Inc.
         and The Administrative Trustees named therein.

4.6      Form of Capital Securities Certificate of HSB Capital II

4.7      Guarantee Agreement between HSB Group, Inc. and The First
         National Bank of Chicago dated as of December 31, 1997 relating
         to HSB Capital II.

4.8      Registration  Rights  Agreement  dated as of  December  31,  1997 among
         Employers Reinsurance Corporation, ERC Life Reinsurance Corporation and
         HSB Group, Inc.