() Transportation Secretary Sean Duffy is taking action against three states accused of failing to enforce English language proficiency standards for commercial truck drivers.

The move comes in the wake of a deadly crash in Florida, in which a truck driver is accused of making an illegal U-turn, killing three people. Authorities said 28-year-old Harjinder Singh, a native of India, answered two out of 12 questions correctly on an English test and later failed additional language and road sign exams.

Federal guidelines require truck drivers to pass roadside English tests and demonstrate the ability to read and speak English, though enforcement is left to individual states.

Duffy has alleged that at least three states issued commercial licenses without meeting those standards.

Singh reportedly obtained licenses in Washington and California, and was pulled over a month before the crash in New Mexico, where police did not administer a required roadside English test.

“He failed full stop, failed. Couldn’t speak the language, couldn’t see, couldn’t understand road signs,” Duffy said. “The bottom line is, follow the rules of DOT in your state, or there will be serious consequences.”

Singh has been charged with three state counts of vehicular homicide and immigration violations.

The crash in Florida sparked a clash between the Department of Homeland Security and Democratic Gov. Gavin Newsom over Singh obtaining a work permit and driver’s license in California. The Trump administration said Singh was in the United States illegally, and Immigration and Customs Enforcement has issued a hold.