This is the 10761st most frequent Russian word.
вспыхнул
"Вспыхнул" means "flashed" or "flared up."
Here, "вспыхнул" describes the sudden starting of fire in the house.
Старый дом внезапно вспыхнул от удара молнии.
The old house suddenly caught fire from a lightning strike.
In this context, "вспыхнуло" is used metaphorically to depict the quick onset of a visible emotional reaction.
Его лицо вспыхнуло от стыда, когда он понял свою ошибку.
His face flushed with embarrassment when he realized his mistake.
Here, "вспыхнул" is used figuratively to describe a rapid rise in interest or enthusiasm.