Cauldron of Ghosts, Chapter 55 wrote:“Target Gamma…now.”
Marinescu keyed in yet another command and a huge shopping center in one of the towers inhabited by citizens was ground zero for another tactical nuke. A larger one, just over one kiloton.
The time was far from ideal, since the lunchtime crowd would have thinned and the evening crowd hadn’t started arrived. But this all needed to be done in a very short span of time. Even as it was, eleven thousand six hundred and three people were killed immediately. Almost as many would die within the next few days from the effects of radiation, burns and radiation poisoning.
Among the people whose lives were spared by the timing were Zachariah McBryde’s mother Christine and his younger sister Arianne. They’d been planning to shop together that evening, after dinner.
They both lived in the building, Dedrick Tower, but their apartments were far enough from the blast that they suffered no injuries. Christine’s apartment was barely even rattled. Arianne’s was closer, and she lost some fragile personal items tossed off their shelves by the concussion. But nothing worse.”
Nothing in here says one way or another whether they were targeted but the immediately previous section had this gem:
[quote"Cauldron of Ghosts, Chapter 55"]
In all, nine thousand, nine hundred and forty-one people were killed outright. Another seven hundred and two would later succumb to their injuries.
The meeting had been sponsored by Bateson University. The speaker had been Mesa’s Assistant Director of Scientific Research. His topic had been Projections for research grants in 1923.
Mesa had just lost a significant portion of its scientific establishment.
One of those slated to speak later that day had been Anastasia Chernevsky. According to the program, she was just returning from a weeks-long stay in a research institute on McClintock Island. Her husband Jules had just entered the auditorium when the blast went off. He’d been looking forward to seeing his wife again. She’d been incommunicado, as was normal procedure for seminars held at that institute.
Jules had been personally invited by Anastasia’s boss, at Collin Detweiler’s instruction.. As always, the Alignment worked in layers. The blast would not only explain Anastasia Chernevsky’s disappearance. By killing her husband it would also eliminate the one person most likely to probe that disappearance.
Chernevsky herself had never been told of the plan, of course. There was no reason to upset her, especially since that would undermine her effectiveness. By the time she found out about her husband’s death, if she ever did, many years would have gone by. Time would have softened her memory and the precise events of that horrible day of carnage so long ago would have been blurred by that same passage of time.
A number of other scientists were supposed to have been there that day, who, in the event, never showed up. Those were the ones who’d already left Mesa as part of Houdini.
The surviving records would, indeed, show that they’d been there. But the blast would have destroyed their physical persons along with the persons of anyone who might have been able to say otherwise.[/quote]
The implication being (in my interpretation) was that they were looking to remove anyone who might look into said family member's disappearance. Keep in mind that the McBrydes were scheduled to go shopping that evening and the blast was described as less than ideal timing due to the rushed nature of the plan.