New Delhi: The national capital woke up to a thick, toxic blanket of smog on Sunday morning as air quality plummeted deep into the 'Severe' category. According to real-time monitoring data from the Central Pollution Control Board (CPCB) and the Delhi Pollution Control Committee (DPCC), Delhi’s overall Air Quality Index (AQI) breached the 400 mark, hovering around 411 during the early morning hours.