A Boeing 777, operated by Asiana Airlines and en route from South Korea, crash landed this afternoon at San Francisco International Airport.
Federal Aviation Administration spokeswoman Laura Brown says the sequence of events that led to the accident is unclear, but footage (below) depicts smoke emanating from the plane as it sits on the tarmac.
Passengers were evacuated via emergency slides and, at this time, no deaths have been reported.
David Eun, a passenger on the plane, has Tweeted a few updates and says the tail ripped off and fire and rescue workers quickly arrived on the scene, tending to the injured.
He wrote soon after finding safety that "a majority of passengers seem ok."
Temperatures were approximately 65 degrees, according to the National Weather Service, and winds were about 8 miles per hour, leading one to believe that weather was not a factor in the crash.
It's not known how many people were on board, but a Boeing 777 can carry between 246 to 300 individuals. We'll update this story as news breaks.
UPDATE: Two people were killed and scores injured, authorities said.
Despite the deaths and scores of injuries - many of them serious - San Francisco Mayor Edwin Lee said at a news conference that "This could have been much worse."
Joanne Hayes-White, the San Francisco fire chief, said there were 307 people on board - 291 passengers and 16 crew - and all had been accounted for.
Authorities said 182 people were taken to one of nine Bay Area hospitals, including 49 with serious injuries. Hospitals reported that the injuries included burns and fractures.
Federal investigators said it was too early to determine a cause. A representative of the National Transportation Safety Board arrived on scene late Saturday.
The investigation is ongoing and may take weeks if not months.
UPDATE: The bodies of two 16-year old girls from China were found on the runway alongside the plane.