Smoked BK9920

[Arct1k]

I was running a BK9920 on my new GTP2 in a car park - Temps seemed ok under 130 for motor and ESC so decided to drop in 5s...

Did a couple of short runs away and back and then brought it in for a temp check - Just as it got to about stationary in front of me - I saw the dreaed puff of smoke

It looks like the MIC29300-5.0BU High-Current Low-Dropout Regulator is the chip that died... I would be interested to know:-

what this chip does
why it would blow
If it is replaceable or if this would cause other stuff to go (not this is way beyond my ability)

Thanks Chris

Gearing & Pics Below

Spur Tooth Count: 52
Pinion Tooth Count: 21
Total Voltage: 14.8
Motor KV: 1853
Tire Diameter (inches): 4.1
Vehicle Speed: 42.98 mph (69.05 km/h)

Spur Tooth Count: 52
Pinion Tooth Count: 21
Total Voltage: 18.5
Motor KV: 1853
Tire Diameter (inches): 4.1
Vehicle Speed: 53.73 mph (86.31 km/h)