what will happen to the upstream components if the database tier fails?

In a multitier website consisting of a web front end, a processing midtier, and a database backend,
what will happen to the upstream components if the database tier fails?
1. The upstream components are unaffected by the database tier.
2. The upstream components will be unavailable.
A design choice must be:

A.
Justified

B.
As cost-effective as possible