One verse

Bhagavad Gita 1.40

1.40

कुलक्षये प्रणश्यन्ति कुलधर्माः सनातनाः | धर्मे नष्टे कुलं कृत्स्नमधर्मोऽभिभवत्युत ||१-४०||

kulakṣaye praṇaśyanti kuladharmāḥ sanātanāḥ . dharme naṣṭe kulaṃ kṛtsnamadharmo.abhibhavatyuta ||1-40||

kula-kṣaye
in destroying the family
praṇaśyanti
become vanquished
kula-dharmāḥ
the family traditions
sanātanāḥ
eternal
dharme
religion
naṣṭe
being destroyed
kulam
family
kṛtsnam
whole
adharmaḥ
irreligion
abhibhavati
transforms
uta
it is said

With the destruction of the dynasty, the eternal family tradition is vanquished, and thus the rest of the family becomes involved in irreligion.