Vaishnava Dharmashastra 22.47

22.47

bhṛgvagnyanāśakāmbusaṃgrāmavidyunnṛpahatānāṃ nāśaucam ||

The relatives of those who have been killed by (falling from) a precipice, or by fire, or (have killed themselves by) fasting, or (have been killed by) water, in battle, by lightning, or by the king (on account of a crime committed by them), do not become impure;