Sound Transit built a short "stub" tunnel under Pine Street between Seventh and Boren avenues to allow light rail trains running in the Downtown Seattle Transit Tunnel (DSTT) to stop and reverse direction.
Stub tunnel construction began in Fall 2004, and was completed in 2007.
The first stage of construction created a construction work area on the north side and two west-bound travel lanes on the south side of Pine Street.
The tunnel was dug out at the surface and the hole capped by a temporary lid or deck that allowed traffic to pass over while construction continued below.
The contractor worked 40 to 80 feet below street level.
In September 2005 when the DSTT closed to be retrofitted, the existing tunnel at Convention Place Station was demolished in order to be adjoined to the new stub tunnel.