SB 4.8.4
duruktau kalir adhatta
bhayam mrtyum ca sattama
tayos ca mithunam jajñe
yatana nirayas tatha
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O greatest of all good men, by the combination of Kali and Harsh Speech were born children named Mrtyu (Death) and Bhiti (Fear). From the combination of Mrtyu and Bhiti came children named Yatana (Excessive Pain) and Niraya (Hell).