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                                                                   Exhibit 10.48

                  ASSIGNMENT OF DSL LINES AND MUTUAL RELEASE

     This agreement ("Agreement") is entered into as of March 16, 2001 (the
"Effective Date") between Rhythms Links Inc., a Delaware corporation, and
Rhythms NetConnections Inc., a Delaware corporation (collectively, "Rhythms"),
on the one hand, and Steel Enterprise Holdings, Inc. (fka Winfire, Inc.), a
Delaware corporation ("SEH"), on the other hand.

     Whereas, SEH is a broadband software developer, consulting firm, and
internet service provider engaged in the provision of Internet connectivity,
web-hosting, email and other services to residential and business customers.

     Whereas, on March 5, 2001, SEH submitted a Plan For Conversion of Debt of
Creditors of Steel Enterprise Holdings to the outstanding creditors of SEH, in
an effort to prevent an immediate filing of a voluntary petition under Chapter
11 of the United States Bankruptcy Code in the United States Bankruptcy Court
for the Central District of California.

     Whereas, pursuant to one or more agreements ("Provisioning Agreements"),
Rhythms agreed to supply to SEH DSL-equipped circuits provisioned over the same
incumbent local exchange carrier's ("ILEC") facilities as the ILEC's local voice
services ("Line-Shared DSL Circuits").

     Whereas, each of Rhythms and SEH has alleged that the other and its
officers have made various intentional and negligent misrepresentations to the
other and have breached various obligations arising from the Provisioning
Agreements.

     Whereas, pursuant to the Provisioning Agreements, Rhythms is currently owed
$964,571 by SEH (the "A/R").

     Whereas, pursuant to the Provisioning Agreements, Rhythms pre-paid SEH
$2,861,000 in funds it has internally designated as Marketing Development Funds
(the "MDF Funds").

     Whereas, it is the desire of the parties hereto to settle and release all
such claims against one another and their respective officers.

     Now therefore, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

     1.  Assignment of Lines.

         (a)  SEH hereby assigns to Rhythms all of SEH's rights to the Line-
              Share DSL Circuits installed by Rhythms and/or ordered from
              Rhythms by SEH and not yet installed (collectively, the "Installed
              or Ordered Circuits"), and SEH shall have no further obligations
              to Rhythms in connection with the Installed or Ordered Circuits.
              Notwithstanding the foregoing, for a period not to exceed sixty
              (60) days following the effective date of this Agreement, SEH
              shall use commercially reasonable efforts to continue to support
              the end users of the installed Line-Shared DSL Circuits (the "End
              Users") until Rhythms has
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              transitioned the End Users to being direct customers of Rhythms or
              a third-party Internet service provider ("ISP"). For the period of
              thirty (30) days, SEH will use commercially reasonable efforts to
              assist Rhythms in the transition of the End Users to being direct
              customers of Rhythms or a third-party ISP, and shall provide to
              Rhythms such customer information as Rhythms may reasonably
              request, including, but not limited to, customer e-mail addresses
              and credit card information.

         (b)  Rhythms acknowledges that not all End Users will elect to become
              customers of Rhythms or a third-party ISP. Accordingly, Rhythms
              agrees that SEH shall not be liable for any cancellations by End
              Users of their Line-Shared DSL Circuit service. Without limiting
              the foregoing, SEH shall not be obligated to pay any cancellation
              fees or other charges to Rhythms.

         (c)  Rhythms shall not be obligated to accept any further orders of
              Line-Shared DSL Circuits from SEH until such time as SEH's
              financial condition improves to the mutual satisfaction of Rhythms
              and SEH. At such time, SEH and Rhythms shall engage in good faith
              negotiations regarding the acquisition by SEH of future end users
              of Line-Shared DSL Circuits.

     2.  Issuance of Series C Preferred Stock. In complete payment, and full
satisfaction, of the A/R and repayment of the MDF Funds, SEH shall issue to
Rhythms 2,034,878 shares of Series C Preferred Stock (the "Stock").

     3.  SEH Representations and Warranties.  To induce Rhythms to enter into
this Agreement and to accept the Stock in payment and complete satisfaction of
the A/R and MDF Funds, SEH herby represents and warrants to Rhythms that:

         (a)  Corporate Existence; Compliance with Law. SEH and each of its
              subsidiaries (a) is duly organized, validly existing and in good
              standing under the laws of the jurisdiction of its organization
              and (b) has the corporate power, authority and the legal right to
              own and operate its property, to lease the property it operates as
              lessee and to conduct the business in which it is currently
              engaged.

         (b)  Corporate Power; Authorization; Enforceable Obligations.  SEH has
              the corporate power, authority and the legal right to make,
              deliver and perform this Agreement and has taken all necessary
              corporate action to authorize the execution, delivery and
              performance this Agreement. No material consent or authorization
              of, filing with, notice to or other act by or in respect of, any
              governmental authority or any other person or entity is required
              in connection with the execution, delivery, performance, validity
              or enforceability of this Agreement. This Agreement has been duly
              executed and delivered on behalf of Rhythms, and constitutes a
              legal, valid and binding obligation of SEH, enforceable against
              SEH in accordance with its terms, except as such
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              enforceability may be limited by applicable bankruptcy,
              insolvency, reorganization, moratorium or similar laws affecting
              the enforcement of creditors' rights generally and by general
              equitable principles (whether enforcement is sought by proceedings
              in equity or at law).

         (c)  Securities. Upon the Effective Date, all shares of Stock to be
              issued pursuant to this Agreement will have been duly and validly
              issued and will be fully paid and nonassessable and free and clear
              of any lien, charge or other encumbrance or claim, and the
              issuance thereof will not be subject to any preemptive or similar
              rights.

     4.  Mutual Release.

         (a)  This Agreement shall be effective as a full and final accord and
              satisfaction in settlement of, and as a bar to each and every
              claim, demand, debt, invoice, trade debt, account receivable,
              account, reckoning, liability, obligation, cost, expense, lien,
              action and cause of action, any party hereto (including any
              affiliate of any party hereto) has, or has had, against the other
              party hereto and/or any of such party's officers, agents,
              directors, shareholders, subcontractors, parents, subsidiaries,
              employees and affiliates (collectively, the "Released Parties")
              arising out of or relating to the Installed or Ordered Circuits
              and/or any and all prior discussions and/or agreements between the
              parties, oral or written (including, without limitation, the
              Provisioning Agreements).

         (b)  In connection with such waiver and relinquishment, the parties
              hereto acknowledge that they are aware that they may hereafter
              discover facts different from or in addition to the facts they now
              know or believe to be true with respect to the subject matter of
              this Agreement, but it is their intention to fully, finally,
              absolutely and forever settle any and all claims, disputes and
              differences which now exist or heretofore have existed
              (collectively, "Claims") between any of the Released Parties
              arising out of or related to the matters described above, and that
              in furtherance of such intention, the mutual releases herein given
              shall be and remain in effect as full and complete general mutual
              releases notwithstanding the discovery of such different or
              additional facts.

         (c)  The parties represent that they have been advised by legal counsel
              and are familiar with the provisions of California Civil Code
              Section 1542, which provides as follows:

         "A general release does not extend to claims the creditor does not know
         or suspect to exist in his favor at the time of
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         executing the release, which if known by him, must have materially
         affected settlement with the debtor."

         Each party, being aware of this code section, hereby expressly waives
         any rights it may have thereunder, as well as under any other statutes
         or common law principles of similar effect.

     6.  Miscellaneous.

         (a)  Effectiveness.  This Agreement shall be effective immediately upon
              its execution and delivery by each party hereto.

         (b)  Representations and Warranties.  Each party hereto hereby
              represents and warrants to each other party hereto that such party
              has not heretofore assigned or transferred, or purported to assign
              or transfer, any of the Claims (or any part thereof) released
              under this Agreement. These representations and warranties are
              deemed to and shall survive the execution hereof by the parties
              hereto. Each party hereto agrees to indemnify, defend and hold
              harmless the other party hereto from and against any claim based
              upon, in connection with, or arising out of any such assignment or
              transfer or purported or claimed assignment or transfer.

         (c)  Governing Law.  Interpretation and enforcement of this Agreement
              shall be governed by the laws of the state of California. The
              federal and state courts of Orange County, California shall have
              exclusive jurisdiction over any actions arising hereunder. In the
              event one or more of the provisions contained in this Agreement
              shall for any reason be held to be invalid, illegal, or
              unenforceable, such invalidity, illegality or unenforceability
              shall not affect any other provision hereof, and this Agreement
              shall be construed as if such invalid, illegal or unenforceable
              provision had never been contained herein. The waiver by any party
              of a breach or violation of any provision of this Agreement shall
              not operate as or be construed to be a waiver of any subsequent
              breach hereof.

         (d)  Successors and Assigns.  This Agreement shall be binding upon and
              inure to the benefit of the parties hereto and their successors
              and assigns; provided, however, that neither party hereto shall
              assign any of its obligations under this Agreement without the
              specific written consent of the other party hereto.

         (e)  Counterpart.  This Agreement may be executed in counterparts, each
              of which shall be deemed to be an original, and which together
              shall be deemed one and the same instrument.
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RHYTHMS LINKS INC.                      STEEL ENTERPRISE HOLDINGS, INC.


By:________________________________     By:________________________________

Its:_______________________________     Its:_______________________________

Date:______________________________     Date:______________________________


RHYTHMS NETCONNECTIONS INC.


By:________________________________

Its:_______________________________

Date:______________________________