While overheating batteries is not a new situation as there have been overheating batteries for likely as long as there have been batteries, scenarios like these are in the news more as of late due to the issues with the Samsung Galaxy Note 7. Following those events, a new report has surfaced today stating that a Samsung Galaxy Note II began to emit smoke in the middle of an IndiGo flight headed from Singapore to Chennai. The device, which was stored in the luggage compartment below the plane, began to to smoke and spark which caught the attention of other passengers who could smell it. That resulted in the airline using a fire extinguisher to put out the sparks, followed by placing the phone in water to be safe.
According to the report the plane was able to land just fine and none of the passengers or airline personnel were hurt in any way, and while this is less serious than many of the situations that took place with the Galaxy Note 7, it goes to show that it's still possible for something to go wrong even with older electronics. Reuters also states that this is the first report of something like this happening with a Galaxy Note II device, suggesting this is a one-off incident.
At the moment there looks to have been no explanation from Samsung as to what caused the issue with the phone, but the report mentions that Samsung is looking into things to figure out what started the problem. Even though the plane made it safely to its destination, passengers on future flights may be requested not to use their Galaxy Note phones on future flights, as India's Aviation regulator (the DGCA) is said to be putting out a notice that requests passengers either leave all Galaxy Note series devices powered off on flights, or simply not bring them on the flight altogether. While that might seem like an extreme measure, it's likely that the Directorate General of Civil Aviation is taking into account this incident as well as the formal recall on the Galaxy Note 7 into their decision on the warning, which makes sense, as the reasoning for it ultimately leads back to the safety of the passengers and the crew.