Earlier this year, there were reports of at least three Tata Nano runabouts channeling The Trammps and going up in Disco(unt) Infernos. Of the three Nanos that got the charbroil treatment, two of them were apparently due to a faulty switch. The third couldn't be explained, so Tata put together a team of 20 employees supplemented by a forensics expert to figure out what was going on.
Without explaining what happened, the team has reportedly "found no manufacturing defects," and according to PTI News, they say that the third incident is unrelated. Furthermore, all Nanos "absolutely safe." As you were, then. Still, in case current Nano owners want to be even more than absolutely safe, Tata will preemptively check any vehicle already in service.
[Source: PTI News]