The washers didn't "explode" ,A mechanical piece of hardware came apart. I don't think any fire was involved. The word explode shouldn't 've used in the case of the washers nor Note 7. .
Per the definition, seems apt. The note 7 ejected hot material when it went, that one dog got badly burned....the washer also threw parts everywhere when that spoke failed. Definition does not mean fire.
ex·plode
ikˈsplōd/
verb
1.
burst or shatter violently and noisily as a result of rapid combustion, decomposition, excessive internal pressure, or other process, typically scattering fragments widely.
"a large bomb exploded in a park"
synonyms:blow up, detonate, go off, burst (apart), fly apart, erupt