of assets, liabilities, revenue and expenses at the date of the consolidated financial statements and reporting periods. The more significant areas  requiring the use of management assumptions and estimates relate to: Actual results may differ materially from these estimates using different assumptions or conditions. For additional information, see  Critical  Accounting Estimates  in  Management’s Discussion and Analysis of Financial Condition and Results of Operations ,  Note 1  of  Notes to Consolidated  Financial Statements  and the risk factors:  “Our development of new ore bodies and other capital costs may cost more and provide less return than  we estimated,” “Our ore reserve estimates may be imprecise,” “Our environmental obligations may exceed the provisions we have made,”  and  “We  are currently involved in ongoing legal disputes that may materially adversely affect us.” We recognize the expected future tax benefit from deferred tax assets when the tax benefit is considered to be more likely than not of being  realized. Otherwise, a valuation allowance is applied against deferred tax assets reducing the value of such assets. Assessing the recoverability of  deferred tax assets requires management to make significant estimates related to expectations of future taxable income. Estimates of future taxable  income are based on forecasted income from operations and the application of existing tax laws in each jurisdiction. Metal price and production  estimates are key components used in the determination of our ability to realize the expected future benefit of our deferred tax assets. To the extent  that future taxable income differs significantly from estimates as a result of a decline in metals prices or other factors, our ability to realize the deferred  tax assets could be impacted. Additionally, significant future issuances of common stock or common stock equivalents could limit our ability to utilize  our net operating loss carryforwards pursuant to Section 382 of the Internal Revenue Code. Future changes in tax law or changes in ownership  structure could limit our ability to utilize our recorded tax assets. As of December 31, 2010, we removed substantially all deferred tax valuation  allowances, with the exception of certain amounts related to foreign net operating loss carryforwards, and our current and non-current deferred tax  asset balances as of December 31, 2012 were $29.4 million and $86.4 million, respectively. See  Note 5  of  Notes to Consolidated Financial Statements  for further discussion of our deferred tax assets. The 2008 credit crisis and related turmoil in the global financial system had an impact on our business and financial position, and a similar financial  event in the future could also impact us. The continuation or re-emergence of the financial crisis may limit our ability to raise capital through credit and  equity markets. The prices of the metals that we produce are affected by a number of factors, and it is unknown how these factors may be impacted by  a global financial event. We maintain defined benefit pension plans for employees, which provide for specified payments after retirement for most employees. The ability of  the pension plans to provide the specified benefits depends on our funding of the plans and returns on investments made by the plans. Returns, if any,  on investments are subject to fluctuations based on investment choices and market conditions. A sustained period of low returns or losses on  investments could require us to fund the pension plans to a greater extent than anticipated. See  Note 8  of  Notes to Consolidated Financial  Statements  for more information on our pension plans. Production may be reduced below our historical or estimated levels as a result of mining accidents; unfavorable ground conditions; work stoppages  or slow-downs; lower than expected ore grades; unexpected regulatory actions; the metallurgical characteristics of the ore that are less economic than  anticipated; or because our equipment or facilities fail to operate properly or as expected. For example, in the second quarter of 2010, mining  activities at the Lucky Friday mine stopped for approximately two weeks due to some deterioration of shaft infrastructure at the #2 Shaft, which is the  mine’s secondary escape way. Upon completion of repairs to #2 Shaft, the mine returned to normal production. In April 2011, a fatal accident occurred  at the Lucky Friday mine resulting in a cessation of operations at the mine for approximately 10 days. In November 2011, an accident occurred as part  of the construction of the #4 Shaft at the Lucky Friday mine, resulting in the fatality of one contractor employee. In an unrelated incident, in December  2011, a rock burst occurred in a primary access way at the Lucky Friday mine and injured seven employees. Each of these events temporarily  suspended operations at the Lucky Friday mine and adversely impacted production. Other closures or impacts on operations or production may occur  at any of our mines at any time, whether related to accidents, changes in conditions, changes to regulatory policy, or as precautionary measures. At the end of 2011, the Federal Mine Health and Safety Administration (“MSHA”) began a special impact inspection at the Lucky Friday mine which  resulted in an order closing down the Silver Shaft, the primary access way from surface at the Lucky Friday mine, until we removed built-up  cementitious material from the Silver Shaft. This occurred despite the fact that the Silver Shaft was not involved in any of the accidents at the mine in  2011. Underground access was limited as the work was performed, and production at the Lucky Friday was suspended until early 2013 as a result. We  resumed limited production at the Lucky Friday in the first quarter of 2013 after completing work on the Silver Shaft and a bypass of the area impacted  by the December 2011 rock burst.  6 [ HL:10-K ]  For further information, see  Management’s Discussion  and  Analysis of Financial Condition  and  Results of Operations .  Mining accidents or other adverse events at an operation could decrease our anticipated production. OPERATION, DEvELOPMENT, EXPLORATION AND ACqUISITION RISKS Returns for Investments in Pension Plans and Pension Plan Funding Requirements Are Uncertain Global financial events may have an impact on our business and financial condition in ways that we currently cannot predict. Our ability to recognize the benefits of deferred tax assets is dependent on future cash flows and taxable income y  mineral reserves, mineralized material, and other resources that are the basis for future income and cash flow estimates and units-of- production depreciation, depletion and amortization calculations; y future metals prices; y environmental, reclamation and closure obligations; y asset impairments; y valuation of business combinations; y reserves for contingencies and litigation; and y deferred tax asset valuation allowance.