[Tijeras_Slim]

The Lancastria was the largest loss of life from a single engagement in World War Two and is also the largest loss of life in British maritime history - greater than the Titanic and Lusitania combined.

The wording can be taken either way, but I get your point.

[Chainmail]

The horrors of that war are hard to comprehend.

[alexander_busek]

The wording can be taken either way, but I get your point.

Indeed, the wording is quite ambiguous. Better:

The sinking of the Lancastria resulted in the largest loss of human life from a single military engagement during WW II...

[I am supposing that the taking of Iwo Jima and the bombings of Hamburg - or of Hiroshima or of Nagasaki - are not considered "engagements" by the author - maybe he means "naval engagement".]

...Further, it resulted in the largest loss of life ever in the whole of British maritime history.

I suspect that that is what the author meant to say.

In any event, any sentence that - even after three re-readings - still leaves room for doubt is an example of poor writing.

Regards,