There isn't a readily accessible, manually operated "emergency fuel cutoff switch" like some older vehicles had on a 2000 Buick Regal LS. Modern fuel systems rely on various safety features integrated into the car's computer systems and fuel delivery components. A crash would trigger safety mechanisms to shut down the fuel pump, for example.
If you're concerned about a fuel leak or other fuel-related emergency, the best course of action is to immediately contact emergency services and move the vehicle away from potential ignition sources. Do not attempt to locate or manipulate any component of the fuel system yourself, as this could be extremely dangerous.
