WASHINGTON (AP) — A string of fiery train derailments across the country has triggered a high-stakes but behind-the-scenes campaign to shape how the government responds to calls for tighter safety rules.

Billions of dollars are riding on how these rules are written, and lobbyists from the railroads, tank car manufacturers and the oil, ethanol and chemical industries have met 13 times since March with officials at the White House and the Pipeline and Hazardous Materials Safety Administration.