LLCs have some good asset protection features that protect your personal assets if someone sues the LLC as owner of the property. However, in your case it is less likely that having your rentals in an LLC will protect them. If the foreclosures result in a deficiency, the bank(s) won't be suing the LLC, they'll be suing you as debtors on the mortgages. The will be able to seek compensation from your assets, and one of your assets is membership in the LLC. Depending on what state the LLC was formed in there may be some protections that make the LLC an unattractive asset to the bank, but you'll need to check with a local lawyer who specializes in asset protection to determine whether the laws of the state where you formed the LLC provide any sort of protection in this sort of situation.
I agree with the other two posts. In general think of this as the bank can try to go after whatever and whomever is guaranteeing the debt. If you and your spouse and your business partner guaranteed the debt (and there is a deficiency judgment) the bank might look to any of you to pay the deficiency. The bank wouldn't try to go after the LLC as an entity but they might execute on your ownership interest in the LLC. They would not need to "pierce the veil" with regard to the LLC but would instead have gone straight to you as an individual (which is the type of situation better planning might have prevented).
It is difficult to say if this situation could have been avoided because the bank, in order to feel comfortable lending to you, would have needed adequate security. They might not have been willing to lend to ABC Rental Property LLC without personal guaranties from the members of the LLC.
In any case, talking to an attorney would probably be a good idea. Sometimes the threat of litigation is enough to tip someone who is on the fence into offering a more favorable outcome. Perhaps you could persuade the bank to accept a deed in lieu of foreclosure and walk away. Good luck.
Disclaimer: This is not to be construed as legal advice. Always seek legal representation before making any important legal decisions.