Abandoned kitten died
One of the two little kittens the caregiver took in didn't make it last night. It was so little (she estimates around 3 days old) that sadly it wasn't unexpected. Another caregiver went into the area and searched the whole night for the mother cat the night before but she couldn't find it. The kittens were also in a box with a t-shirt, so they could well have been dumped.
The caregiver nursing the kittens asked why someone would dump them so young - she reasoned surely if there was a mother cat in the flat, it didn't hurt the owner to keep them a little longer before dumping them. That's absolutely true, but who knows why these people do the things they do?