shì / gù / de / jù / tǐ / yuán / yīn / shàng / wèi / jiě / jué / diào / chá / réng / zài / jìn / xíng / zhōng

事故的具体原因尚未解决，调查仍在进行中。

The specific cause of the accident remains unsettled, and the investigation is still under way.