Melbourne's metro train network faces delays during one of its busiest weeks following a level-crossing smash that's left one man dead and 13 people injured.

Police have quizzed and released a 59-year-old truck driver, seizing his phone and taking a blood sample, after a prime mover smashed through boom gates and into the path of a train in Abbots Rd, Dandenong South, around 11.40am (local time) on Saturday.

The train, travelling towards Cranbourne with 30 passengers on board, struck the truck's trailer, which was loaded with vegetables, causing its front carriage to jackknife, derail and overturn. Other carriages also tipped and came to rest beside the tracks.

A 30-year-old Gisborne man found trapped under rubble in the front carriage died at the scene after suffering cardiac arrest, while the injured train driver was trapped for an hour before he could be taken to hospital, Ambulance Victoria said.

Transport officials warn it could take a week to reopen the Cranborne line.

Trains on tracks either side of the site will also be out of action, which will likely affect the entire network as it enters one of its busiest weeks for the year catering for the Spring Racing Carnival.

- AAP