Our Site was down this morning with lots of stack error messages. I am investigating what happened

This is a messagein  windows System logs:

The World Wide Web Publishing Service (WWW Service) did not register the URL prefix https://*:443/ for site 3. The necessary network binding may already be in use. The site has been disabled. The data field contains the error number.

And these are some Stack errors :

1-
Type : System.Data.SqlClient.SqlException, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) Source : .Net SqlClient Data Provider Help link :
Errors : System.Data.SqlClient.SqlErrorCollection
Class : 20
LineNumber : 0
Number : -1
Procedure :
Server :
State : 0

2-
Type : System.InvalidOperationException, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : Timeout expired.  The timeout period elapsed prior to obtaining a connection from the pool.  This may have occurred because all pooled connections were in use and max pool size was reached.
Source : System.Data
Help link :
Data : System.Collections.ListDictionaryInternal
TargetSite : System.Data.ProviderBase.DbConnectionInternal GetConnection(System.Data.Common.DbConnection)
Stack Trace :    at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)

3- This happened multiple times
04/14/2010 03:19:42
Type : System.InvalidOperationException, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : Timeout expired.  The timeout period elapsed prior to obtaining a connection from the pool.  This may have occurred because all pooled connections were in use and max pool size was reached.
Source : System.Data

4- This happend multiple times
Type : System.ArgumentException, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : Item has already been added. Key in dictionary: 'host'  Key being added: 'host'
Source : mscorlib
Help link :
ParamName :
Data : System.Collections.ListDictionaryInternal
TargetSite : Void Add(System.Object, System.Object)
Stack Trace :    at System.Collections.ListDictionaryInternal.Add(Object key, Object value)
   at DotShoppingCart.Commercial.OrderPipeline.OrderProcessorProvider.Proccess(String host, IConfigurationSource cfgSrc)
   at DotShoppingCart.Commercial.OrderPipeline.ProcessorProvider.Run()
   at DotShoppingCart.Commercial.OrderPipeline.RunnableProvider.StartRun()

5-
Type : System.ArgumentException, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 Message : Item has already been added. Key in dictionary: 'host'  Key being added: 'host'
Source : mscorlib
Help link :
ParamName :
Data : System.Collections.ListDictionaryInternal
TargetSite : Void Add(System.Object, System.Object)
Stack Trace :    at System.Collections.ListDictionaryInternal.Add(Object key, Object value)
   at DotShoppingCart.Commercial.OrderPipeline.TaskProvider.Proccess(String host, IConfigurationSource cfgSrc)
   at DotShoppingCart.Commercial.OrderPipeline.ProcessorProvider.Run()
   at DotShoppingCart.Commercial.OrderPipeline.RunnableProvider.StartRun()