While eating at the university cafe, students see a waiter's serving tray tilt, and the food and beverages he had been carrying spill all over four people. "what a careless, clumsy idiot," they mumble to themselves as they resume eating. they have just committed an attributional bias called: ?

This is known as the fundamental attribution error. 

The fundamental attribution error refers to the phenomenon where we explain others' behavior based on internal factors such as their abilities, shortcomings, personality and traits while underestimating the influence of external factors outside their control that impact their outcomes or actions.