My Dad was located in CA and had caregivers that came in for shifts paid a flat rate for a 24-hr period. He passed and now we received a letter of demand. Any advice?

As per your answer to another responder below, you did not have a contract with these people; you were not paying these people other than as POA or Guardian or some such as far as I can see. They can try to get money from Dad's estate, would have to win a lawsuit to do so, and you are likely correct that they feel there are deep pockets here and have some attorney they want to make a settlement with them. This should all be done with once that attorney finds out there is no estate.
The executor of Dad's will is responsible to handle this now, and whatever estate Dad has pays TO take care of this. My guess is that the attorney for Trust and Estate your executor hires can return a "dead, no estate" letter to the attorney who is acting for the parties threatening suit and this will be over with quickly.
Do not discuss or respond in any way to these people; that could go against you. In fact, the more "dumb" you are as to any of the details of this other than an innocent response of "I have no idea of Dad's contract with these people; if I come across any I will let you know. I only helped with his scheduling" would likely be best. Don't "go there" with responses such as "Dad paid the rate requested, and now, blah blah blah...."
Just keep in mind you are the innocent party who has no idea of any of this. Turn all communications over to the executor of Dad's will or Trust and let that person handle this with the Trust and Estate or probate attorney.

IMO, your Dad owes this money not you. And since it looks like there is no inheritance, they cannot get any money. Did Dad have a contract with them?

I would have a lawyer write them a letter telling them that their agreement was with your Dad. The family is saddened by the letter of demand they sent. Its felt you were treated very well during their employment. They received bonuses and severance after Dad passed. If they were not happy with their wages at time of employment, it should have been brought up then. That the cost of care for Dad depleted his retirement accts, his savings and stocks. Since the house has a Mortgage it will be sold to pay it off. SS and any pension stopped at his death. There is no inheritance. His children are not responsible for the cost of his care.

Hopefully, you wrote checks for everything. I also hope you changed the locks on Dads house. Sorry to say, this is why you keep things professional when hiring aides. I know, its hard. They were there for him. How did you receive their hours? Or you just paid them the same thing every week? IMO, they cashed their checks and by doing that they agreed to payment. If they had a problem it should have been brought up then.

Was their letter from a lawyer? If so, then it needs to be addressed by a lawyer. Otherwise, they are fishing.

Some clarifications:

1. Letter of demand from whom? The individual caregivers, or an agency?

2. Does the demand letter itemize the dates, times, as well as recap what was paid and what allegedly was not paid? If not, that's a necessity.

Was the letter of demand written by an attorney on their behalf?

So your father was paying the caregivers under the table? Was the "very loose" contract he had with each of them in writing?

I don't know what they mean by "wages not received". What exactly is "lost wages"?

It sounds like a bit like extortion to me.

If they were paid to the penny for what was agreed upon up until your dad's passing, then their wages have been received and they have no leg to stand on.

I can't imagine. Ugh.

I am a principal of Crisis Coaching. I consult on Eldercare and related pending Bills, as a federal advocate and independent lobbyist.

You need to talk to a labor and estate lawyer.
Take the contract and payment records with you.

You don't directly owe the money - unless you personally cosigned ( hope you didn't!). The estate owes the money. Life insurance is separate. It doesn't have to be used by beneficiaries to pay estate bills.

Going rate 2022 is $28/ hr on avg for caregivers. Graveyard shift / overnight pays higher. If you included meals that isn't included in the $28. That is just a perk-- unless they contractually agreed that each meal was worth say $3 and it was deducted from the pay rate. Stay above minimum wage, around $16/ hr. and you won't fall below probably.

If they were paid in full what they agreed to for rate and it was above min. wage, I think a labor lawyer will probably say they aren't owed more.

If the estate is bankrupt, no one else owes the money. Mortgage payment comes first when house is sold, taxes and any liens paid.

You can talk to multiple lawyers here for $0-25 for first 30 minutes.

I am still a fan if pre-paid legal plans. For around $30/ mo you can have a lawyer retained for fast needs. Legal Zoom and Legal Shield are two I know of in US.

I can give you the name of one local highly respected conservatorship lawyer in LA area who does "eldercare legal seminars." Her name is Susan Geffen. She has a huge local following. She helped me a lot through her webinar info when my father was dying. I followed her events around the area up til COVID shutdown. She, like other lawyers, can practice anywhere in the state. You can tell her I referred you, if you want. We stay in touch by email. Susan or her husband Joel can refer you on to other lawyers. I work more national and international level supporting adult children who don't live near parents, training on a spectrum of related eldercare issues. www - dot - susanbgeffenlaw - dot com

My gut hunch- I am not a lawyer:

You may have the hassle, and probably do have a positive outcome.

Care4dad707, did you have contracts for each caregiver, or were they from an Agency and it is the Agency asking for more money which would be not the norm? The Contract should state what is the hourly rate for normal hours, and if the caregiver can, in fact, work overtime.

For my Dad, I used a well known Agency and the cost was $20k per month, this was a few years ago. The Agency had each caregiver bring their own meals. Rarely was there overtime, if a caregiver was unable to make her shift, the Agency called in another caregiver.

Dad never had any damage caused by the caregivers. The damage he had was from trying to "drive" his walker around the house. I found as I am getting older, there are a lot of oops moments.

I would tell them to go kick rocks or sue your dad. How did they loss wages, your dad passed away.

dont ignore the requests but reply you are not going to pay it. There is a legal reason for this. Let them sue your dead dad.

If you can locate the original contract, give it to a lawyer in that community in CA. He or she can draft letters to get them to cease and desist.