I live in an appartment, I think the dry soil brought mine down. They also don't love the darkness of my appartment, I can only keep low light junglish ones and ones who dont mind a bit of overwatering and underwatering.Oh yeah, in case I'm not totally patronising you! When it gets to winter time, they often appear to be dying, but in fact are just 'hibernating', and will often 'recover' in the spring when conditions improve (obviously need to protect if you get frosts etc, better indoors over winter, I suspect). Apparently a lot of people mistakenly throw them out thinking they've had it!
For watering, I use a saucer under the pot and fill from there normally, and let it soak into the 'soil'. It's apparently good for the roots to let the water run out for a day or more from time to time, to encourage them to grow in search of better supply of water, but don't let the soil dry out! It's quite sponge like (mine is anyway) and absorbs a lot, but in the window on a sunny day, evaporates much quicker.
My basils were doing the worst, they truly love gardens.