Four of 23 people rushed to hospital after exposure to toxic fumes were under intensive care yesterday. Hundreds of students were evacuated from two Phra Pradaeng schools in Thailand after fumes wafted across the Chao Phraya River from a plastics plant. Local police said the Siri Vitthaya and Bangchak Vitthaya schools had to close after the emission from the Srithepthai Plaschem plant, where a ventilator had exploded.