The National Transportation Safety Board (NTSB) does a fine job investigating these matters and in particular features a section entitled "lessons learned" which applies to many kinds of transport. http://www.ntsb.gov/events/journalist/lessons/lessons.htm
The incident which gave rise to the "lessons learned" recommendations came in 2005 when a group of elderly passengers were attempting to flee a hurricane. Other motorists alerted the bus operator that the right rear tire hub was glowing red.
Upon exiting the motorcoach the driver saw flames in the right rear wheel well. They attempted evacuation and the bus was engulfed in flames and smoke and 23 people were killed.
The NTSB performed a detailed investigation and suggested that ongoing evaluation take place concerning the frequency of bus fires, the effectiveness of fire mitigation and prevention and a prohibition on wheel seal or hub lubrication leaks.
They also suggested that the National Highway Transportation Safety Board mandate detection systems for wheel well temperatures to avoid fires.
The bottom-line, fires on buses are deadly and measures to protect passengers, particularly elderly passengers, must be implemented.