Are these sentences correct:
1-They robbed a train last week carrying gold.
2-They robbed a train last week that was carrying gold.
The noun phrase is broken, but the meaning is clear. I think people say things like this but it seems to me that they do not work in formal English.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
And remember you can also use the passive (unless the context had previously mentioned who "they" are):
Last week, a train carrying gold was robbed
A train carrying gold was robbed last week.
Please be aware that I'm neither a native English speaker nor a teacher.