A train has hit a bus from a special needs school, killing at least four people on board—including two children. Nine people were thought to have been on the bus, at least seven of them children of high school age, at the time the crash took place Tuesday morning in Flanders, a northern region of Belgium. “With great dismay, I learnt of the tragic accident in Buggenhout, where a school bus was struck by a train,” Bernard Quintin, the Belgian interior minister, posted on X. “My thoughts go out to the victims and their loved ones.” The collision took place at a crossing, where a spokesperson for Infrabel, the rail network operator, described the impact as “extremely violent.” Another spokesperson claimed the “barriers were down and the traffic lights were red” when the crash occurred. “We do not know how the accident could have happened,” they went on. “The train was already braking. The train driver did apply the emergency brake, but was unable to avoid a collision.”