The ride was reopened Friday at the Chelsea Community Fair, 15 miles west of Ann Arbor, after it passed an inspection by state regulators.
Witnesses told The Ann Arbor News that the children fell 15 to 20 feet out of a Ferris wheel cab on Thursday night. Alex Keszler said the cab "just dumped the kids out."
Chelsea Police Chief Ed Toth and fair president Rick Boham say it's still not clear how it happened. Boham said an 8-year-old boy has been released from a hospital while his 16-year-old sister remains there for observation.
Boham said the girl is expected to make a full recovery.