Physical classes for Class 10 and 12 students in Delhi have been suspended due to hazardous air quality, with all studies shifting online, announced CM Atishi on Monday. The capital's smog levels exceeded 60 times the WHO's recommended limit. The city's air quality remains in the "severe" category, worsened by factors like crop residue burning and industrial emissions. Stage 4 of the Graded Response Action Plan (GRAP) has been activated to curb pollution.