The incident occurred at 12:45 pm (1045 GMT) just before passengers boarded the plane which was scheduled to fly to Los Angeles.
"The aircraft's nose gear unexpectedly retracted while it was parked," a spokeswoman for the airline told AFP.
Cabin crew and ground staff were on board and several were injured and received medical treatment, the airline said.
A Lufthansa Boeing 787 aircraft collapses onto its landing gear while parked at Frankfurt Airport, Germany, on June 4. Video by X/FlightRadar24
Another Lufthansa spokesperson told AFP on Thursday evening that the wounded, which included two of its crew members, sustained only light injuries.
