The Additional Commissioner of Police, Traffic - Mr Sanjay Arora has been quoted as saying, "We are keeping all options open and will investigate to find out if the accident was due to mechanical failure or careless driving or use of a mobile phone."
However, he also claimed that the police are not ready to jump into any conclusion in haste. "It is too early to jump to conclusions," added Mr Arora.
The driver, who took shelter from the police to avoid attack from the angry mob and relatives of the injured people, claimed that he lost control of the vehicle as his seat got displaced.
According to sources, the MTC bus (route No 17 M), which was plying between Vadapalani area and Parry's Corner in Chennai, was bought in 2007 and drivers of Metropolitan Transport Corporation (MTC) were not ready to drive the vehicle as its expiry date has already been over.
The accident occurred when the bus took a blind U-turn but could not keep the control and fell off from the flyover. Initial reports claimed that 30 people were injured but later police claimed that a total of 38 people were seriously injured, though there was no report of casualty.