When he crashed a school bus into a semi-trailer Thursday morning in Largo, sending four high school students to the hospital, veteran Pinellas County school bus driver Bernard Lee Gant marked his 11th preventable accident since joining the school system 24 years ago.He resigned later in the day after being barred from driving pending a drug test and review of the accident by district staff, according to district spokesperson Lisa Wolf. Gant declined to comment.Wolf called Thursday’s crash "concerning," adding that seven of the 10 prior incidents also involved Gant, 67, hitting a car in front of him while driving a school bus. He also has hit a parked car, backed into a parked car and hit a curb, records show.“Pinellas County schools expects safe transportation for our students every day and we hold our drivers to high standards,” Wolf said in a statement.Gant’s first accident as a bus driver happened in April 1994, less than two months after he was hired. He received eight letters of warning for accidents spanning from 1997 to 2014, before another accident in 2015 resulted in a three-day suspension, records show.Wolf said all of the accidents were considered minor, including the crash on Thursday, which happened about 6:30 a.m. on Ulmerton Road near 58th Street, according to the Florida Highway Patrol.Troopers said the bus struck the rear of a semi-trailer, which was stopped at a red light. Four of the six students on the bus were sent to Johns Hopkins All Children’s Hospital for treatment of minor injuries.The students had been on their way to Seminole High and Richard O. Jacobson Technical High.Neither Gant, a resident of St. Petersburg, nor the driver of the semi-trailer, 45-year-old William A. Morales of Valrico, was injured, troopers said. Gant was cited for careless driving.Contact Megan Reeves at [email protected] Follow @mareevs.