Milwaukee County sheriff's spokeswoman Fran McLaughlin says the passenger notified flight crew at about 6:45 a.m. Wednesday of the shell while the Detroit-bound plane was still at General Mitchell International Airport.
She says deputies and Transportation Security Administration officials removed the passengers from the plane and screened them again but found nothing. She says a canine unit also swept the plane and didn't find anything.
The passengers again boarded the plane. Delta spokesman Michael Thomas says the flight was delayed about an hour and landed safely in Detroit at 9:55 a.m.