UPDATE: Charges dropped over Melbourne explosion

A Melbourne man accused of endangering police and firefighters in a gas bottle explosion in a self-harm attempt has walked free from court, with a magistrate finding he could not have foreseen the tragedy.

Twenty-one charges against Leon Firth, 40, over the explosion at his Middle Park flat which injured six emergency services workers in January have been dropped.

Magistrate Jelena Popovic said Firth had locked himself in his bedroom with a gas bottle in a serious suicide attempt.