Nostradamus Prophecy: The Assassination of JFK

The ancient work will be accomplished,
And from the roof evil ruin will fall on the great man:
They will accuse an innocent, being dead, of the deed:
The guilty one is hidden in the misty copse.
(Century 6, Quatrain 37)

The great man will be struck down in the day by a thunderbolt,
The evil deed predicted by the bearer of a petition:
According to the prediction another falls at night,
Conflict in Reims, London, and pestilence in Tuscany.
(Century 1, Quatrain 27)

As per his prediction - JFK was shot in the day, at 12 noon, and his brother Robert Kennedy was shot at night, at 1 am. The last line dates the assassinations. For there were student riots in London and Paris in 1968, and in 1966 a flood hit Florence that prompted fears of pestilence. JFK was shot in 1963 and his brother in 1968. The alleged conspiracy that surrounded the assassination was the subject of another of Nostradamus' quatrains.

Lee Harvey Oswald was reputed to have shot Kennedy from the sixth floor of the Book Depository, is this 'the roof' that is mentioned in second line? Or is 'the roof' a metaphor for the conspiracy performed by the CIA, previously Kennedy's protection, his 'roof'. The third line suggests that Lee Harvey Oswald was in fact innocent, and 'the misty wood' of the fourth line may describe either the trees around the grassy knowle, or the misty woods of the secret service.