Passage: In the same year, the first version of Rich Wilson's Lifting Shadows, an authorized history of the band's first twenty years, was released.The 2007–08 Chaos in Motion Tour started off in Italy. Dream Theater played in the Gods of Metal concert on June 3, 2007., as well as various other European festivals including the Netherlands' Fields of Rock Festival, UK's Download Festival, the French festival Hellfest Summer Open Air alongside Megadeth, Korn, Mastodon and Slayer. The North American leg of the tour began on July 24 in San Diego, California and wrapped up on August 26 in Philadelphia, Pennsylvania. They played with opening acts Redemption and Into Eternity. The Chaos In Motion Tour continued for the rest of the year and into 2008, playing shows in Asia, South America and, for the first time, Australia.On April 1, 2008, a two-disc compilation album entitled Greatest Hit (...and 21 Other Pretty Cool Songs) was released by the band. The title jokingly references the song "Pull Me Under", the band's only significant radio hit. It also includes three song re-mixes from their second album, Images and Words, five edited versions of previously released songs, and a track from a single B-side. Unlike most greatest hits compilations, Dream Theater was actively involved with the album, coming up with the track listing that they felt best represented their musical careers.

Question: Which American city did Dream Theater's 2007 tour start in?
San Diego, California