“But the change up to 90 F will almost certainly be insignificant until you get up to temperatures about 800 F.”
My 1948 Harley has steel pistons. They are regularly subjected to the temperatures associated with burning gasoline. (above 90) They are still running after 59 years.
Steel isn’t human. It doesn’t mind hot weather.
Since it unknown at this time, what caused this collapse, nothing can be ruled out. I am certain when day dawns in about nine hours, some of the possibilities as to why this happened will be ruled out within twenty-four hours or two working days, or an answer could be found in the same time span.
The cause will be known within a matter of weeks, would be my best guess, from reading this thread, and listening to the news. But I am no expert, so take all I just typed with a grain of salt.
Prayers for all those affected, and extra prayer for the victims and their families.