A/N As Mike's the youngest of the Arlesdale engines of the show, Rex dies next. The smaller engines have a shorter lifespan in my Thomasverse, like rats compared to bigger animals, like dogs or primates. My FanFiction buddy said in canon, the older narrow-gauge engines seem to have lived so long only due to being overhauled. But the NWR engines, like Thomas, seem stronger, though they get ill at times. So, the non-NWR engines die during or shortly after Mainland dieselization, except if they're younger, like Mike, Jock and Ivo Hugh. The younger little engines die shortly before Emily, in the case of all but Ivo Hugh, who dies in when the standard-gauge are dying.
It seemed like just another day for the miniature engines, but then something happened to change everything. Rex had a dreadful accident and was pronounced dead.
The engines who were friends of the miniature engines had a meeting in Arlesburgh. Rex's controller said, "Rex had a fatal accident.", dabbing his eyes with his handkerchief. Rex's crew sniffed and sobbed into their handkerchiefs as well. Rex's engine friends were in tears as well, buffer pressing each other and comforted by their drivers. Alistaire was completely open, wailing with grief as a fellow Arlesdale engine, Jock, and him pressed buffers. Mike and Frank pressed buffers and quietly sobbed in a corner. Thomas pressed buffers with Edward, as the tank engine gave a tearful speech. His driver pressed a cloth to his eyes.
Thomas said, through wailing sobs and sniffles, "R-Rex w-was a-a R-Really U-Useful E-Engine. W-We sh-shall m-miss h-him dr-dreadfully, b-but w-we m-must c-caryy o-on a-and b-be R-Really U-Useful E-Engines, b-because h-he w-would w-want th-that. W-We c-can gr-grieve a-as w-we r-remember h-him wh-who's g-gone t-to Th-The B-Big R-Railway I-In th-the Sk-Sky.". He then wailed his broken heart until he had no more tears to cry.
The Arlesdale Railway was closed to allow the engine time to grieve and have a memorial service for that friend. It was held in Arlesburgh, so other gauge engines than the miniatures engines could be there. The more emotional ones shed a great many tears, like Thomas and Alistaire. Edward accompanied Thomas, to give him buffers to press in his grief.
The railway reopened and Alex, a miniature diesel, took Rex's place. She was gentle, dreamy, sympathetic and enthusiastic. Her driver thought Alexandra was a bigger name than her, so he called her Alex. Life took on a more normal rhythm on the Small Railway.
A/N Some engines, like Jock, Olivia and her friend, a reader mentioned will be mentioned in the Mike deathfic as also dead, but glossed over. My fan couldn't remember Olivia's friend's name and I can't find anything about them.