  The 2s_{1/2} state of hydrogen is metastable and overpopulated in HII
regions. In addition, the 2p states may be pumped by ambient Lyman-alpha
radiation. Fine structure transitions between these states may be observable in
HII regions at 1.1 GHz (2s_{1/2}-2p_{1/2}) and/or 9.9 GHz (2s_{1/2}-2p_{3/2}),
although the details of absorption versus emission are determined by the
relative populations of the 2s and 2p states. The n=2 level populations are
solved with a parameterization that allows for Lyman-alpha pumping of the 2p
states. The density of Lyman-alpha photons is set by their creation rate,
easily determined from the recombination rate, and their removal rate. Here we
suggest that the dominant removal mechanism of Lyman-alpha radiation in HII
regions is absorption by dust. This circumvents the need to solve the
Lyman-alpha transfer problem, and provides an upper limit to the rate at which
the 2p states are populated by Lyman-alpha photons. In virtually all cases of
interest, the 2p states are predominantly populated by recombination, rather
than Lyman-alpha pumping. We then solve the radiative transfer problem for the
fine structure lines in the presence of free-free radiation. In the likely
absence of Lyman-alpha pumping, the 2s_{1/2}-2p_{1/2} lines will appear in
stimulated emission and the 2s_{1/2}-2p_{3/2} lines in absorption. Searching
for the 9.9 GHz lines in high emission measure HII regions offers the best
prospects for detection. The lines are predicted to be weak; in the best cases,
line-to-continuum ratios of several tenths of a percent might be expected with
line strengths of tens to a hundred mK with the Green Bank Telescope.
