[CAMcEwan]

I planted some radish and they came up like soldiers. They're over an inch high now, but today two just gave up the ghost. More than a dozen still going strong, but two of their fellows just keeled over and died in the last 24 hours. Any idea why?

[Salmo]

I would guess that something is eating the roots. The most likely suspects are maggots of the cabbage root fly. Dig a plant out with some soil, put it on to a flat surface and see if you can see any bugs. Carrot root fly maggots eat the small roots and also burrow into the root.