1. woke ( signal word yesterday; specific time)
2. walked (same sentence, also signal word yesterday)
3. was walking (signal word while; longer action)
4. saw (shorter action that interrupts the longer action)
5. had called (Order first the police was called, then the road was blocked)
6. was blocked (passive for past simple; there is no subject; by zombies)
7. was called (passive for past simple; there is no subject; by zombies )
8. took (Past simple; its not a longer action and there is no order, but all of this still takes place in the past)