No builders are facing criminal charges, says Ontario Police Detective Mike Macias. Rather, but they're being asked whether or not any Ontario employees has ever asked them for money or other favors to speed up the building process.

Nearly 4,000 letters were mailed this week to developers, contractors and related professionals who have done business with Ontario building officials over the past three years. One LA-based commercial developer who received the mass-mailer tells GlobeSt.com that the letter urges builders to contact Ontario officials if they've ever been asked to supply cash or gifts "beyond the scope of normal business."

The Inland Empire has been among the nation's fastest-growing regions for the past 30 years. Homebuyers were attracted to the region in the 1970s and '80s by its inexpensive housing, and the homebuilding boom was soon complemented by hundreds of new commercial real estate projects.