。
The thunderstorm threw the train schedule into chaos.
Literal
Thunderstorm [because-of-のため] train [possessive-の] schedule [subject-が] became-disordered.
ダイヤ is a katakana abbreviation of ダイヤグラム ('diagram'), used in railway parlance to mean 'train timetable / schedule.' A specialized loanword that learners encountering Japanese transit news will see often. 乱れる ('become disordered / disrupted') is intransitive.