Police gave the all-clear about 2 hours later.
Metro Airport spokesman Mike Conway said a worker noticed the suspicious item during screening and it burned out the tube, The Detroit News reported.
A bomb squad member wearing protective gear placed the item, described as similar to a laptop or small suitcase, into a bomb container unit outside the North Terminal about 2 hours later.
Conway said travelers, many headed to spring break destinations, were moved to the old Smith Terminal as a precaution.
Police cruisers blocked all North Terminal arrival and departure lanes during the evacuation, the News said.
"It's a very busy day and the terminal was very, very crowded," Conway said. "All the airlines have early morning flights."
Conway said he didn't have information about the person traveling with the suspect item.