Judges 4:16

There was not a man left. — The massacre in all battles in which the fugitives have to escape over a river and contend with a storm is always specially fatal. The memory of this terrible carnage was preserved for years, together with the circumstance that the soil was enriched by the dead bodies (Psalms 83:10). Similarly at Waterloo, the year after the battle a blaze of crimson poppies burst out over the plain, and the harvests of the subsequent years were specially rich.

“The earth is covered thick with other clay,
Which her own clay shall cover.”

The scene of the battle of Marius at Aquæ Sextiæ was long called Fourrières (a corruption of Campi Putridi) for the same reason; and the site of Cannæ is still known as Pezzo di Sangue.