Someone broke my heart and one week later Some accident happened to his father and his father,is it a karma affecting their family?
No, a person never have to face karma of another
Mahabharata - Shanti Parva - Moksha Dhama Parva -Chapter 291
नायं परस्य सुकृतं दुष्कृतं चापि सेवते ।
करोति यादृशं कर्मं तादृशं प्रतिपद्यते
One never has to enjoy or endure the good and bad acts of another. Indeed, one enjoys and endures the fruits of only those acts that one does oneself
Death is common for all living beings. But linking it to any scripture's ideas without knowledge of scriptures is ignorant behaviour
Moksha dharma parva, Chapter 299:
There is no fixed time for the acquisition of righteousness. Death waits for no man. When man is constantly running towards the jaws of Death, the accomplishment of righteous acts is proper at all times.
— Parāśara, Shanti Parva, Mahabharata Book xii.299
Each and every karma affects parents until brahmacharyashram is not over.
Once one sage sandipani had a son Nachiketa. And nachiketa innocently noticed yagya performed by his father.
Sage cursed him and donated him to death.
Nachiketa went to yamloka, and surrendered to yama. yama told him that he can get 3 boons but he asked for his father's wellness and reduction in anger.
The God of death gave him what he asked and send him back to his father.
There is another story where child had mistakenly mislead and angered on mother.
Lord Shani was out and just came back to home and seeked food from his mother goddess chhaya.
The food was not ready so chhaya could not fulfill shani dev's desire. Angery Lord shani kicked mother. Resulting Shane's one leg which he used to kick was broken for lifetime. And mother had to be mother of broken legged shani dev.
So i will say by time the secrets will give society all results of fulfillment. Stay calm. Nobody know when where and how God gives result. Just pray for mercy. Do not overthink.