Not likely. You should take the time to meet with and consult with a Spokane probate attorney. Most probate attorneys provide for a free consultation. Go to the "find a lawyer" tab and look for a probate attorney to talk with. I am sorry for your loss.
"Estate" of your brother means any checking and savings account balances, any real estate and personal property, anything of value. That is the estate. Someone will need to probate the estate, however. Nevertheless, no one in his family is liable. However, if he has a spouse, she may be liable for his debts, assuming they were incurred during the marriage. Condolescences.
Unless and until we sign an agreement for legal services, I am not your attorney. Contact me at 509-951-2514 or firstname.lastname@example.org for a free consultation. The information contained in this answer is not intended as legal advice applicable to your case or situation, as I don't represent you or know your facts.
You may also want to talk to a probate attorney about how a family award or creditor claims procedures may possibly be used to reduce the debts if there is a spouse or children.
This answer provides general legal information and should not be construed as legal advice to be applied to any specific factual situation. It is not intended to create and does not create an attorney-client relationship. The attorney writing this post is licensed in Texas and Washington only and the laws of your jurisdiction may differ.