Speeding occurs even before the official rush hour on Delhis roads. On Tuesday,22 students,their teachers and three others in a school bus had a narrow escape when the vehicle overturned at a traffic signal in South Delhis RK Puram around 7 am. According to the police,another bus sped in and hit the school bus while it was turning left at RK Puram Sector-1 crossing,near Munirka Bridge. The bus fell on its left,thereby jamming the escape route. The vehicles rear glass had to be broken to take out those inside. The GD Goenka Public School bus was taking students to the Vasant Kunj institution at the time. School authorities said at least 10 students and two teachers received minor injuries in the incident. The school did not cancel the days examination,which began at 7.40 am as per schedule,authorities said. The accident took place around 7 am when our bus was coming to school with students, principal D M Sharma said. The bus was turning left at the red light when a chartered bus tried to jump the signal and hit it on the left side. Officers said the chartered bus,which also ferries schoolchildren at times,was carrying only the driver and cleaner at the time. Four students and two teachers were taken to Safdarjung Hospital and six students were taken to Fortis Hospital,closer to our school in Vasant Kunj, a school official said. Principal Sharma said all students were given first-aid and discharged. The students came to school and wrote their exams, Sharma told Newsline. Everyone is safe. Tannu Gupta,a Class X student who was in the bus,said there was initial chaos after the bus toppled but the situation was brought under control soon. Her mother Shalini Gupta,who came to the school after learning about the mishap,said Tannu was taken to Fortis Hospital and discharged after first-aid. Police officers said a case against the driver of the chartered bus,identified as Randhir Singh,was registered on the basis of a complaint by school bus driver Mukhtar Ahmed. School authorities maintain that Ahmed was adhering to speed limit regulations. He was driving at normal speed, a school official said. School buses have speed governors that do not allow drivers to go beyond 40 km per hour. The police have seized both buses. Prima facie,it appears the chartered bus driver was at fault and we have registered a case at RK Puram police station, a senior officer said. What experts sayS N Shrivastava,Joint Commissioner of Police (Traffic): Since the school bus was hit at a certain angle by the chartered bus,it rotated on its vertical axis and lost balance. Buses are vulnerable as their centre of gravity is higher. If both vehicles are plying at speed,then the impact is more. T K Malhotra,president,Automobile Association of Upper India: It seems another bus was competing with the G D Goenka school bus,and the driver could have become confused leading to the accident. We train bus drivers at 85 schools and have had a training programme earlier with G D Goenka,too. Rohit Baluja of Institute of Road Traffic Education: Buses are stable vehicles mechanically. A bus can topple only when it takes a sharp turn,which could be because of any reason at very short turning radius. Story of the mishap* 7 am: RK Puram Sector 1 crossing,near Munirka Bridge* School bus coming from New Friends Colony towards Vasant Kunj* As it takes a left at the traffic light,a chartered bus speeding in from the inner side hits school bus on left side* Bus overturns,on left side,blocking doors and trapping children inside* 22 students,2 teachers,guard,conductor and driver were in bus* Rear glass of bus broken to take out children