Dictionary of Greek and Roman Biography and Mythology/Herennius 10.
10. M. Herennius, decurio of Pompeii, about b. c. 63. Shortly before the conspiracy of Catiline, Herennius was killed by lightning from a cloudless sky. This was accounted a prodigy in augural law, and the death of Herennius was reckoned among the portents which announced the danger of Rome from treason. (Plin. H. N. ii. 51.)