Can the scenario for someone's death be written so that there is a possibility of other people dying? So you can't use the Death Note to kill someone else. If you write something like: 


  "John Zerto burns himself to death after he killed his boss"


John would simply die of a heart attack so he couldn't kill his boss. But if you would write: 


  "John Zerto dies after a heart attack after he tried to shoot his boss"


That could work. After 6 minutes and 40 seconds, John would take out his gun and try to shoot his boss. And because there's a chance his boss could survive, it could possibly work. So what do you think? Could this work?
Rule X (I think) specific says

Whether the cause of the individual's death is either a suicide or
accident, if the death leads to the death of more than the intended,
the person will simply die of a heart attack. This is to ensure that
other lives are not influenced.

So if written in the Deah Note &quot;John Zerto burns himself to death after he killed his boss&quot; it won't be possible.
However, the second example you gave &quot;John Zerto dies after a heart attack after he tried to shoot his boss&quot; might be possible since a gunshot don't necessarily kill people so if he has a gun (because if he can't get one he will die of a heart attack) the DN will make John Zerto shot his boss in a way he won't be killed, but if it's not possible to the boss the got shot and not get killed like he have bad health and will be dead the DN will prevent John to shoot his boss and will die of a heart attack.
And this only for the difference since it is not written that he shot his boss to kill him just shot to shoot him, the DN talked about other deaths, not injures.