Hazrat, Death in Service is a benefit offered by most western employers where they pay 3/4 times your salary to your spouse/dependants. I believe you become eligible after certain few years of service.
Wa Alaikum As Salaam,
The ‘Death in service’ benefit will be halal for your family since it is given from the monies which you and your employers contributed to while you were employed at the company.
And Allah Knows best
Mufti Waseem Khan