Sources said more than 500 patients were undergoing treatment at the Chengalpattu GH and on Tuesday around 10.30 pm out of which 13 patients who were already critical died without responding for treatments one by one in a few minutes since the doctors could not provide oxygen supply for them. 

When the oxygen supply ran out, the hospital staff took the oxygen from the ambulances and managed to give it to a few patients who were desperately in need of oxygen but could not be of much help, eyewitnesses alleged. By around midnight the oxygen cylinders from the SRM and Karpaga Vinayaga medical college reached the Chengalpattu GH and the situation was brought under control. However, still 13 patients lost their lives. 

Later, Chengalpattu district collector A John Louis visited the hospital and held inquires. The collector said that the hospital had enough amount to oxygen for the patients but there was a problem in the main tube so it could not be supplied. All the 13 patients were extremely critical so it was helpless. The collector said the inquiry is on and if the fault is on the hospital action would be taken. Sources said Chengalpattu GH is capable of storing 23,000 tonnes of oxygen and only around 3000 tonnes are being used so oxygen will not be a problem in Chengalpattu GH.