Two boys pushed a slab of concrete of a bridge, which smashed a train windscreen, killing the driver. They were convicted and lost their appeal. The CA held that one could be guilty of manslaughter if the defendant intended an act that was unlawful ad dangerous and that the act inadvertently caused death. The test for “dangerous” is objective: do all reasonable people recognise the danger. Lord Salmon: Reg V Lamb was only overturned due to the judicial misdirection, NOT because the trial judge erred in law. Salmon says that some crimes require speicific intent (e.g. murder which requires intent to murder or cause GBH) whereas some are basic intent (requirement of intent to do the actions that lead to harm: NOT an intent that the consequences themselves should happen). Manslaughter is basic intent, so that causing death by “unlawful and dangerous activity” IS manslaughter, as is criminal negligence. This answers in the affirmative that where a defendant did not foresee that his actions may cause harm, it is still possible to convict him of manslaughter (provided he was engaged in an unlawful and dangerous act, or where he was criminally negligent).