Been playing it for the past several days. Good stuff. I started off in the new city (though old cities can be retrofitted with the new facilities introduced in the new pack).

The husband was a firefighter (his life goal was to save 40 people) and the wife was an inventor (her goal was to create three types of life). After an experiment exploded, the wife learned a sim on fire couldn't extinguish themselves. She called the fire department but burned to death before they got there (it wasn't her husband who answered, he was on another call).

The husband grieved for a while, then married a pretty stylist who was approximately his age. They had only one kid, who is probably going to follow in the footsteps of his almost-mom (though he has a very wide skillset) by becoming a scientist. Kids can experiment too, and he is already a more accomplished inventor than his father's first wife. He has invented quite a few things and has survived being on fire once (his mother was around to put the fire out) and electrocuted twice.

Firefighting is pretty cool. It can be done on autopilot (just tell the sim to put out all the fires) unless there are people to be saved, in which case one has to decide the order in which one wants to do things (and the angle of approach, sometimes doors have to be broken down to save sims). Firemen can steal valuables and can talk with people after they've saved their households.