driving down the road and booom from right under me, and then the car shuts off. turns over, but no start (has spark). any clues?? how does one check the voltage to the injectors, and how much should it be?

 

looked at the car a little more in depth (seeing as how i was on the side of the road in the dark last night trying to figure it out) and i noticed the intake tubing had come off the air flow sensor box thingy. so i put it back on and to my amazement the car started, perfect, however that does not explain what blew up. when i say blew up i really dont know what happened, but i felt it under the seat and it just sounded like something wacked the underside of the car. any suggestions?