  We report on investigations of the chiral and deconfinement aspects of the
finite temperature transition in 2+1 flavor QCD using the Highly Improved
Staggered Quark (HISQ) action on lattices with temporal extent $N_\tau=6$ and
$N_\tau=8$. We have calculated several physical observables, including the
renormalized Polyakov loop, strangeness fluctuations, the renormalized chiral
condensate and the chiral susceptibility in the crossover region for physical
values of the strange quark mass $m_s$ and light quark masses $m_l=0.2m_s$ and
$0.05m_s$. We compare our findings with previous calculations that use
different improved staggered fermion formulations: asqtad, p4 and stout.
