Panic attack: Last time Delhi shook so much was 55 years ago

Not since 1960 had the capital shook so much. The earthquake that rattled Delhi just before noon on Saturday was the severest in 55 years, measuring 5 on the Richter scale locally. Although no casualties were reported here, the intensity and duration of the tremors sent people scurrying out of homes and offices.Those who were stuck on high floors froze in panic and prayed with hearts drumming deafeningly.

After three seismically quiet years--the last notable quake occurred in Bahadurgarh, 30km from Delhi, on March 5, 2012--the city took a few moments to realize what was happening.

The tremors started at 11.41am and continued for about two minutes. But when they were over, people hesitated to return indoors. Nobody wanted to take a chance and they looked for signs--a suspended bulb or ceiling fan that wasn't swaying. Hardly had they returned indoors when a second wave of tremors struck at 12.18pm. This time, people reacted faster, grabbing their phones and keys and making a dash outdoors. "We were downstairs for about 10 minutes when the first tremors were felt. Just as we thought the worst was over and turned on the TV for news, the tremors started again," said Nitish Saxena, a resident of Mayur Vihar Phase I.

L S Rathore, director of India Meteorological Department, which monitors earthquakes, said a temblor's intensity reduces away from the epicentre. "While the epicentre recorded 7.9 on the Richter Scale, it was about 6.5 in Gorakhpur and about 6 in Lucknow. In Delhi, the intensity was 5.

"On August 27, 1960, Delhi was shaken up by an earthquake that had its epicentre between Delhi Cantt and Gurgaon. About 75% of the buildings around the epicentre developed cracks and minor damage to Red Fort and Rashtrapati Bhavan was also reported. About 100 people were injured by falling debris and in stampedes. Although the quake was first classified as a magnitude-6, researchers now say it was more likely a magnitude-4.8.

To take stock of the situation, LG Najeeb Jung called a high-level meeting with CM Arvind Kejriwal, police commissioner B S Bassi, the MCD commissioners and other senior officials on Saturday evening. Officials reported hairline cracks in three buildings in the East district, two in the South district and one in North district. PWD officials checked all flyovers and reported them safe.

Delhi lies in 'seismic zone IV' or an area of high damage risk from earthquakes. Parts of it lying on the Yamuna floodplains are especially vulnerable. Although earthquakes occur regularly here, most of them cannot be felt, but a magnitude 6 or 7 quake is possible and could cause extensive damage to life and property as, architects and planners say, 95% of the buildings have not been built in accordance with the safety code.Many are not certified by structural engineers and don't have completion certificates from civic agencies.