The behavior of an electric field in a gravitational field is analyzed. The electric field of a charge accelerated in free space is studied using the equations of STR, and it is found to be curved due to the acceleration of the charge. The electric field of a charge located statically in a gravitational field curves too due to the fall of the electric field in the gravitational field. In both these cases, the stress force created in the curved electric field acts as a reaction force which leads to the creation of electromagnetic radiation -- both by a charge accelerated linearly in free space, and by the electric field falling in a gravitational field. Maxwell equations are used to show how the energy flow of the falling electric field serves as the source of the energy carried by the radiation.