Sir: The PTI shutdown call for Karachi, which was started early Friday morning, kept the provincial metropolis shut off. PTI supporters blocked all major roads by burning tires, using trucks or staging sit-ins on streets, preventing people from reaching their work and students from attending their educational institutions. The sit-ins were staged at major traffic intersections of the city including University Road, Teen Talwar in Clifton, Five Star Chowrangi in North Nazimabad. Although the flight schedule remained unchanged, people struggled to reach the airport due to the blockades. Javeria Nasir Karachi