On 'Undercover Boss' (Sun., 6PM ET on CBS), Larry O'Donnell, COO of Waste Management, went undercover to spend some time working on one of his garbage trucks.

But when a grateful customer wrote a sweet note to one of his employees, O'Donnell got understandably emotional. "I didn't think I'd be having these kinds of emotional issues riding on the back of a garbage truck," he said. "I had no idea."

Watch the video after the jump.On 'Undercover Boss' (Sun., 6PM ET on CBS), Larry O'Donnell, COO of Waste Management, went undercover to spend some time working on one of his garbage trucks. But when a grateful customer wrote a sweet note to one of his employees, O'Donnell got understandably emotional. "I didn't think I'd be having these kinds of emotional issues riding on the back of a garbage truck," he said. "I had no idea."