Legal Question in Business Law in California

That's impossible to say without knowing the terms of the lease and sublease.

Perhaps true, as Mr. Starrett answered, that one cannot be certain without reading the lease and sublease. However, I'd say that as a general rule, leases survive the death of the lessor or lessee. This follows the even more general rule that contracts survive the death of a contracting party unless the contract involves personal services. For example, if I contract with Picasso to paint my portrait, and Picasso dies, the contract does not allow his student or his executor to find someone else to do the painting. Somewhat similarly, if I die, Picasso is not bound by the contract to paint the portrait of my heir. However, most ordinary business are not for personal services -- and this includes most leases, especially leases of business premises. I'd therefore surmise that a court would find the contract is still valid and enforceable.