The computer in my high school classroom recently started acting up. After watching me struggle with it, one of my students came up and took over. "Your hard drive crashed," he said.
I called the computer services office and explained, "My computer is down. The hard drive crashed."
"We can't just send people down on your say-so. How do you know that's the problem?"
"A student told me," I answered.
"We'll send someone over right away."