De or het treinkaping?

The correct Dutch article is:

de treinkaping

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

How to use treinkaping

the treinkapingde treinkaping
this treinkapingdeze treinkaping
that treinkapingdie treinkaping
our treinkapingonze treinkaping
your treinkapingjouw treinkaping
every treinkapingelke treinkaping
which treinkaping?welke treinkaping?
a big treinkaping / the big treinkapingeen grote treinkaping, de grote treinkaping