Good morning Curtis,
Do you receive a hard copy statement, or have access to your account online? If not, contact your HR department, or whoever handles benefits for your employer, or former employer, and make sure they have a current mailing and email address for you. Once the plan administrator has current contact information for you, you should be able to see your statements and account balance, whether you choose to receive the information in hard copy, or choose to receive an email notice of it being posted.
Once you have this information in hand, you can contact the financial institution which holds the funds, and begin the discussions about closing the account.
Hope this helps.