Why would a tire catch fire?

Tire fires are normally the result of arson or improper manipulation with open fire. ... Burning tires are heated, and, as they have a low thermal conductivity, they are difficult to cool down. Moreover, they frequently burn inside even if they are extinguished from outside, and easily reignite when hot.

Can a wheel bearing overheat?

If a wheel bearing overheats, the hot lubricant breaks down and can cause scoring and even etching of the bearing surface. Also, water and other corrosive elements can create this condition, which lead to spalling down the road. Burned or oxidized lubricant may leave a dark coating on bearing surfaces.