while的连词用途

Thirty people have been confirmed as having died while battling a forest fire in southwest Chinas Sichuan Province,authorities said Monday.

老师，连词的修饰用途具体怎么样用，从属连词，并列连词都是连接句子，短语，词与词之间的它的修饰用途与形容词修饰名词，副词修饰动词一个原理吗？

Thirty people have been confirmed as having died while battling a forest fire in southwest Chinas Sichuan Province,authorities said Monday.

while引导的省略形式的时间状语从句修饰的是实意动词die, 即死亡发生在救火过程中。die用目前分词完成体是由于要表示死亡是发生在/confirm/i之前。