Questions & Answers about Było tyle dymu, że nie widziałam drzwi.
Było is the neuter singular past form of być (to be), and here it is used in an impersonal/existential way, similar to English there was.
So:
- Było tyle dymu = There was so much smoke
In this kind of sentence, Polish often uses neuter singular było, even though dym is masculine. The focus is not really the smoke was... but rather there was...
Compare:
- Był dym. = There was smoke / Smoke was present
- Było dużo dymu. = There was a lot of smoke
The second structure commonly uses było.