Plane accidents were caused very rarely but they were dangerous if they were caused there will be very low chances to be saved if plane crash occurred. Plane guides will always take care of passengers. And the plane will checked by the airport members very well before its takeoff. Even they take many things to be safe some accidents do occur because of different problems. Mostly accidents take in air due to engine failures and technical problems.
In this cases there are very less chances of saving passengers but at present many scientists and engineers working on the new method of building a plane which would be safe to journey. Shocking Place Accidents.
Source : Air Crash Investigation