  IceCube is a kilometer scale neutrino observatory now in construction at the
South Pole. The construction started in January 2005 with the deployment of 76
sensors on the first string and four surface detector stations. Nine strings
and 32 surface detectors are in operation since February 2006. The data based
on calibration measurements, muons and artificial light flashes are consistent
with performance expectations. This report focuses on design, construction
experience and first data from the sensors deployed in January 2005.
