De or het treinstoring?

The correct Dutch article is:

de treinstoring

Rule Words ending in -ing: almost always de. See the rule

How to use treinstoring

the treinstoringde treinstoring
this treinstoringdeze treinstoring
that treinstoringdie treinstoring
our treinstoringonze treinstoring
your treinstoringjouw treinstoring
every treinstoringelke treinstoring
which treinstoring?welke treinstoring?
a big treinstoring / the big treinstoringeen grote treinstoring, de grote treinstoring