A, B and C are life tenants in a type 2 multiple holder life estate that continues until the last of them die, at which time the remainder interest owner, a college, becomes the owner. The college has a vested remainder interest.
A dies. The new owners are A Jr., B and C until both B and C are dead.
A Jr. also dies. The new owners are A the third, B and C until both B and C are dead.
B dies. The new owners are A the third, B Jr., and C.
C dies. The interest of A the third, B Jr. and C each terminate and college's vested remainder interest becomes a fee simple absolute interest.
@DaleM is correct that "It’s not fee simple because the interest ends when the last survivor dies."
In real life, a more common scenario would be for a widow to have a life interest and then convey it to one or more her children for her life (a life estate per autre vie), or for her to mortgage her life estate and default, leaving the lender with ownership of the property for the remainder of her life.
Of course, actually, any kind of legal life estate is now very rare and far more often, legal ownership would be vested in a trustee, and beneficial ownership would be as is set forth in a trust agreement with no particular terminology used to describe the different kinds of rights that can be afforded to the equitable beneficiaries of the trust.