A truck carrying highly toxic chemicals exploded on a highway in northwest China’s Tianshui City early Saturday morning. The truck was rear-ended, leaving one person dead and another person injured. After the explosion, the 41 tons of phosphorus pentasulfide disintegrated into a poisonous gas, shrouding part of the city. Local authorities at 10:30 a.m. said the air quality in the urban area had returned to normal. The accident is still under investigation.