A German airliner owned by Germanwings Airlines has crashed in the French Alps Tuesday morning. The 148 passengers and crew are feared dead, and rescue operations are currently underway. The crash site, however, is in an inaccessible area.

Lufthansa, owner of the low-budget Germanwings, announced on Twitter that the plane had crashed. The plane was traveling from Barcelona to Dusseldorf and carried 144 passengers with six crewmembers.

Flight 4U9525 took off from Barcelona-El Prat Airport at 9:55 a.m. local time and was traveling above the French Alps when it sent out a distress call at around 10:45 a.m., according to NBC News. The plane crashed soon after at an altitude of 6,550 feet.

French President Francois Hollande released a statement expressing his condolences for the victims and their families but added he feared the worst.

"The conditions of the accident, which have not yet been clarified, lead us to believe there are no survivors," he said.

Spain’s King Felipe cut his state visit to France short and returned home. Spanish Prime Minister Mariano Rajoy also expressed his condolences. German Chancellor Angela Merkel said "harrowing news" has put Germany in "deep mourning” and said the suffering of victims' families is "immeasurable."

Flight Radar, which tracks flights all over the world, reported on Twitter that Flight 4U9525 followed the same path as other planes on the same route and only diverged at the last moments before crashing.

Reuters reports Spain’s deputy prime minister confirmed that 45 aboard the plane are Spanish nationals. The rest of the passengers are believed to be German and Turkish, according to what King Felipe told reporters.

German air experts as well as the country’s transport minister, Alexander Dobrindt, are on their way to the crash site, according to Reuters.  

"In these difficult hours our thoughts are with all those who must fear their relatives are among the passengers or crew members," Foreign Minister Frank-Walter Steinmeier said.

The A320 involved in the crash was 24-years-old, according to Reuters, but the model is considered a workhorse with many airlines with more than 3,500 in operation worldwide.

French Interior Ministry spokesperson, Pierre-Henry Brandet, said search and rescue operations were underway but the operation is expected to be “extremely long and extremely difficult," The Assciated Press reports. 

The plane crashed in a remote area usually used for skiing. Chancellor Merkel said she would travel to the site on Wednesday and said an investigation is underway.

"We still don't know much beyond the bare information on the flight, and there should be no speculation on the cause of the crash," she said. "All that will be investigated thoroughly."

According to Agence France-Presse, the aircraft nosedived for 8 minutes soon after reaching a crusining altitude of 38,000 feet. The pilot, accoridng to Germanwings, had 10 years of experience and the A320 had undergone maintance checks in the summer of 2013.

Among the 67 German citizens believed aboard are 16 school children returning from a trip in Spain, reports Reuters. Two teachers were traveling with the teenagers.

The local French newspaper Le Dauphine published the first photo of the crash site, which has been circulating through Twitter.