Worksafe investigating Vic trench death

A young Melbourne worker was preparing to lay sewer pipes before he was killed in a trench collapse, authorities say.

The 19-year-old was working on land being prepared for a new housing site at Cranbourne East when a four metre deep trench collapsed, Worksafe confirmed on Thursday.

They're investigating the accident, which happened about 2pm on Wednesday.

It took emergency services about seven hours to find the man and retrieve his body.