MacBook just stopped

My friend was watching a movie on her Mac Book and everything went blank all the sudden (screen and sound) the light indicates the computer is turning on and off but other than that the computer is un responsive. Even the eject button for the movie is not working and the movie is still inside. She said just after the computer went blank it made a low level screech sound.

What do you think is there a way we can check something

Sincerely,

Kristina