A woman suspected of driving under the influence and two passengers are dead following a crash on Highway 12 in San Joaquin County Sunday afternoon, the California Highway Patrol said.

The crash site sits along a bustling corridor for traffic heading onto the highway or deeper into Napa, with a gas station to the north and a park-and-ride to the south. The offramp, lined with scattered trees and plants, was shut down until noon as investigators worked to determine how fast the sedan was traveling before impact.

Law enforcement officials are warning drivers not to count on luck to avoid trouble if they decide to drink and drive on St. Patrick's Day.

Law enforcement officials are warning drivers Monday not to count on luck to steer clear of trouble if they decide to drink and drive on St. Patrick's Day.