5. Indebtedness

The following table discloses certain information regarding our indebtedness:



	Outstanding Balance at						Interest Rate at March 31, 2013		Effective Interest Rate at Issuance		Maturity Date
	March 31, 2013			December 31, 2012			Interest Rate at March 31, 2013		Effective Interest Rate at Issuance		Maturity Date
Mortgage Loans Payable, Net	$	745,832		$	763,616		4.03% - 8.26%		4.03% - 8.26%		January 2014 - September 2022
Unamortized Premiums	(151		)	(161		)
Mortgage Loans Payable, Gross	$	745,681		$	763,455
Senior Unsecured Notes, Net
2016 Notes	$	159,524		$	159,510		5.750	%	5.91	%	1/15/2016
2017 Notes	55,386			55,385			7.500	%	7.52	%	12/1/2017
2027 Notes	6,066			6,066			7.150	%	7.11	%	5/15/2027
2028 Notes	51,264			55,261			7.600	%	8.13	%	7/15/2028
2032 Notes	11,501			11,500			7.750	%	7.87	%	4/15/2032
2014 Notes	80,040			79,683			6.420	%	6.54	%	6/1/2014
2017 II Notes	106,752			106,745			5.950	%	6.37	%	5/15/2017
Subtotal	$	470,533		$	474,150
Unamortized Discounts	2,187			2,570
Senior Unsecured Notes, Gross	$	472,720		$	476,720
Unsecured Credit Facility	$	18,000		$	98,000		1.904	%	1.904	%	12/12/2014

Mortgage Loans Payable, Net

During the three months ended March 31, 2013, we paid off and retired prior to maturity mortgage loans payable in the amount of $14,283. In connection with these prepayments, we recognized $$371 as loss from retirement of debt for the three months ended March 31, 2013.

As of March 31, 2013, mortgage loans payable are collateralized by, and in some instances cross-collateralized by, industrial properties with a net carrying value of $927,157. We believe the Operating Partnership and the Company were in compliance with all covenants relating to mortgage loans payable as of March 31, 2013.

Senior Unsecured Notes, Net

During the three months ended March 31, 2013, we repurchased and retired the following senior unsecured notes prior to maturity:



	Principal Amount Repurchased	Purchase Price
2028 Notes	4,000	4,566

In connection with this repurchase prior to maturity, we recognized $779 as loss from retirement of debt for the three months ended March 31, 2013, which is the difference between the repurchase price of $4,566 and the principal amount retired of $4,000, net of the pro rata write off of the unamortized debt issue discount, the unamortized deferred financing costs and the unamortized settlement amount of the interest rate protection agreements related to the repurchase of $2, $28 and $183, respectively.

Indebtedness

The following is a schedule of the stated maturities and scheduled principal payments as of March 31, 2013 of our indebtedness, exclusive of premiums and discounts, for the next five years ending December 31, and thereafter:



	Amount
Remainder of 2013	$	10,626
2014	153,811
2015	49,862
2016	295,309
2017	174,153
Thereafter	552,640
Total	$	1,236,401

Our unsecured credit facility (the “Unsecured Credit Facility”) and the indentures governing our senior unsecured notes contain certain financial covenants, including limitations on incurrence of debt and debt service coverage. Under the Unsecured Credit Facility, an event of default can occur if the lenders, in their good faith judgment, determine that a material adverse change has occurred which could prevent timely repayment or materially impair our ability to perform our obligations under the loan agreement. We believe that we were in compliance with all covenants as of March 31, 2013. However, these financial covenants are complex and there can be no assurance that these provisions would not be interpreted by our noteholders or lenders in a manner that could impose and cause us to incur material costs.

Fair Value

At March 31, 2013 and December 31, 2012, the fair values of our indebtedness were as follows:



	March 31, 2013				December 31, 2012
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Mortgage Loans Payable, Net	$	745,832	$	794,940	$	763,616	$	814,915
Senior Unsecured Notes, Net	470,533		517,288		474,150		516,943
Unsecured Credit Facility	18,000		18,031		98,000		98,192
Total	$	1,234,365	$	1,330,259	$	1,335,766	$	1,430,050

The fair values of our mortgage loans payable were determined by discounting the future cash flows using the current rates at which similar loans would be made based upon similar leverage levels and similar remaining maturities. The current market rates we utilized were internally estimated; therefore, we have concluded that our determination of fair value for our mortgage loans payable was primarily based upon Level 3 inputs. The fair value of the senior unsecured notes was determined by using rates, as advised by our bankers, that are based upon recent trades within the same series of the senior unsecured notes, recent trades for senior unsecured notes with comparable maturities, recent trades for fixed rate unsecured debt from companies with profiles similar to ours, as well as overall economic conditions. We have determined that our estimation of the fair value of our fixed rate unsecured debt was primarily based upon Level 3 inputs. The fair value of the Unsecured Credit Facility was determined by discounting the future cash flows using current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining term, assuming no repayment until maturity. The current market rate utilized for our Unsecured Credit Facility was internally estimated; therefore, we have concluded that our determination of fair value was primarily based upon Level 3 inputs.