Downtown Pi Opening

Employees prepare for the Wednesday, May 23, 2012 grand opening of the Pi location in downtown St. Louis. The wood paneling on the walls and ceiling is reclaimed and restored from a barn on a Missouri farm. (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, across from the convention center, on Wednesday, May 23, 2012. The wood paneling on the walls and ceiling is reclaimed and restored from a barn on a Missouri farm. (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, across from the convention center, on Wednesday, May 23, 2012. The booths are made of shipping pallets recovered from around the city. (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, across from the convention center, on Wednesday, May 23, 2012 (KMOX/Michael Calhoun)

Downtown Pi Opening

Employees prepare for the Wednesday, May 23, 2012 grand opening of the Pi location in downtown St. Louis (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, across from the convention center, on Wednesday, May 23, 2012 (KMOX/Michael Calhoun)

Downtown Pi Opening

Employees prepare for the Wednesday, May 23, 2012 grand opening of the Pi location in downtown St. Louis. The location is the second major tenant of the Mercantile Exchange complex -- formerly the Saint Louis Centre mall -- to open, after the Embassy Suites hotel. (KMOX/Michael Calhoun)

Downtown Pi Opening

Employees prepare for the Wednesday, May 23, 2012 grand opening of the Pi location in downtown St. Louis (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, in the shadow of the 600 Washington office tower, on Wednesday, May 23, 2012 (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, across from the convention center and Edward Jones Dome, on Wednesday, May 23, 2012 (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, literally on-top of the convention center MetroLink station, on Wednesday, May 23, 2012 (KMOX/Michael Calhoun)

Downtown Pi Opening

Pi pizza opens its fifth location in downtown St. Louis in the Mercantile Exchange, across from the convention center, on Wednesday, May 23, 2012 (KMOX/Michael Calhoun)