About the tragic limousine fire on the San Francisco Bay's San Mateo Bridge on Saturday, May 4, 2012....  

Every driver should have the $12 Emergency Hammer (multi-function, seat belt cutter, too) in their car, especially Limosines or other very closed vehicles. The tool, available at any auto parts store and some big box stores, quickly shatters automobile windows for easy escape in cases where the doors won't open due to crash damage, submerge in water, or, fire, such as this limo tragedy. See: 
http://www.autopia-carcare.com/life-hammer-escape-tools.html?gclid=CI-K4IL-i7cCFc47OgodIXQAgw I have no affiliation with this company, of course.

Reference article: 
http://mountainview.patch.com/articles/experts-ponder-what-trapped-the-limo-victims-11693ebe#comment_7253308