C#.NET - problem trying to download files via ftp

I've got the following method that is throwing an error...



        public static void Download(String strFileName)
        {
            FtpWebRequest ftp = null;
            Stream ftpStream = null;
            FileStream fs = null;
            FtpWebResponse response = null;

            try
            {
                fs = new FileStream(strPath + strFileName, FileMode.Create);
                ftp = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpTxt + strFileName));
                ftp.UseBinary = true;
                ftp.Credentials = new NetworkCredential(crdUsername, crdPassword);
                ftp.Method = WebRequestMethods.Ftp.DownloadFile;
                response = (FtpWebResponse)ftp.GetResponse();
                ftpStream = response.GetResponseStream();
                int bufferSize = 2048;
                int readCount = 0;
                byte[] buffer = new byte[bufferSize];

                readCount = ftpStream.Read(buffer, 0, readCount);         <======= Line that throws the Error
                while (readCount > 0)
                {
                    fs.Write(buffer, 0, readCount);
                    readCount = ftpStream.Read(buffer, 0, bufferSize);
                    System.Console.WriteLine(readCount.ToString() + " - " + buffer.ToString());
                }

            }
            catch (Exception ex)
            {
                StringBuilder strError = new StringBuilder();
                strError.Append("FTP_Error_");
                strError.Append(DateTime.Now);
                strError.Append(".txt");
                Database.Log_Error(strError.ToString(), ex.ToString());
            }
            finally
            {
                ftpStream.Close();
                fs.Close();
                response.Close();
            }

        } // End of Download()



The line indicated in the code that throws an error says that connection is closed.  There may or may not be some error elsewhere in the code that is causing an error at this line.  But I am unfamiliar with this type of process and don't know where to look to find answers.