An emergency response at the Darwin Airport has been declared a false alarm after a pair of fire trucks raced across the tarmac to seemingly save a landed United States V-22 Osprey.

On Tuesday, morning, passengers and staff were left confused when the airport came to a stand still as two fire trucks entered the airstrip to pull up alongside the US Marine aircraft.

Civilian onlookers watched with anticipation, only for the fire and rescue teams to stand down and return to their bays, with airport operations resumed a short time later.

There was no emergency and no problem with the aircraft.

The lawsuit, filed by the families of Sax, Carlson, Strickland and Rasmuson, accuses Boeing, Bell Textron, Rolls Royce Corps and Rolls Royce North America of negligence, negligent and fraudulent misrepresentation, and the failure to warn.

Tim Loranger, the lawyer representing the families in the lawsuit, told CNN on Thursday that ultimately the lawsuit alleges that the aircraft the Marines were on was known to have a defect but “insufficient steps have been taken to correct it.”

The lawsuit comes months after another deadly V-22 Osprey crash off the coast of Japan, which resulted in the deaths of eight US Special Operations airmen. The US military grounded its entire fleet of V-22 Ospreys in December as a result. That grounding guidance was lifted in March this year; officials said at the time an investigation identified a “materiel failure” responsible for the crash.

Col. Brian Taylor, the program manager of the Naval Air Systems Command V-22 joint program office, told reporters in March that the crash resulted from an “unprecedented” component failure, though he declined to say what component specifically failed or how.

The American military has taken over an investigation into the death of three Marines during a training exercise on a remote island off the Northern Territory.

NT Police were leading the response after a horror military aircraft crash on the Tiwi Islands on Sunday August 27.

There were 23 troops on board the tilt-rotor military aircraft when it went down, with the two pilots and crew chief understood to have sacrificed their lives to avert a catastrophic crash killing all on-board.

Under the Commonwealth Defence Visiting Forces Act, the Territory coroner was barred from holding an inquest into the three marines’ deaths with the initial reports passed onto the American authorities.

Three American marines have been killed in a horror crash during a military exercise off the coast of the Northern Territory.

The Marine Rotational Force Darwin confirmed three of their personnel had died, while another five were flown to Royal Darwin Hospital in serious condition following an Osprey crash over the Tiwi Islands at 9.43am, Sunday.

He said the aircraft, with 23 personnel on board went down while transporting troops during a routine training exercise, known as Predators Run, near Pickataramoor, Melville Island, 80km north of Darwin.

“Recovery efforts are ongoing,” a MRF spokesman said.

The cause of the incident is under investigation.

Ten Marine Corps MV-22B Ospreys have arrived in Australia’s Northern Territory as part of a 2,500-strong rotational force, the Marine Corps said Tuesday.

The Ospreys, from Marine Corps Base Hawaii’s Marine Medium Tiltrotor Squadron 363, are deployed to Royal Australian Air Force Base Darwin, according to a Marine Corps statement and information released Friday by the U.S. Department of Defense with photographs of the aircraft.

The tiltrotors, air crew and support personnel make up the air combat element of Marine Rotational Force — Darwin, which began its annual seven-month rotation last month.

The 12th contingent of the rotational force since 2012 will practice expeditionary operations, geographically distributed communications, non-combatant evacuation, embassy reinforcement, humanitarian assistance/disaster relief and rapid projection of combat power