There are Mr. A and Mr. B. They are conjoined twins who each has their own set of organs except for the heart. I write the name of Mr. A while imagining his face, with the cause of death being falling from the top of Tokyo Tower head first. Let's say the difference in height between the two is less than 1 cm. Will Mr. B also die?

According to [**How to Use: XXVI**](http://deathnote.wikia.com/wiki/Rules_of_the_Death_Note#How_to_Use:_XXVI), item 2:

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> Even though only one name is written in the Death Note, if it influences and causes other humans that are not written in it to die, the victim's cause of death will be a **heart attack**.
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However, a heart attack will also kill Mr. B.

Additionally, [**How to Use: X**](http://deathnote.wikia.com/wiki/Rules_of_the_Death_Note#How_to_Use:_X), item 2 stated:

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> 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**.
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This question is a bit different than [the one proposed as possible duplicate](https://anime.stackexchange.com/questions/7415/can-writing-in-the-death-note-influence-others). In the proposed question, the death of the pilot or the surgeon doesn't necessarily means that the people in the plane or the one in the surgery will 100% die. There is a delay before they actually die. Surgery is rarely done by only one doctor. It usually is done by a team of doctors, so the other doctors can still save the patient. Flying a plane is also the same. There is also the co-pilot. In the case of my question, killing Mr. A is the same as killing Mr. B since they share the same heart with no delay whatsoever to save Mr. B.