An Amazon Air cargo plane overshot the runway while attempting to land at Miami International Airport, killing five people and seriously injuring five more.
The Boeing 767-300 cargo aircraft crashed just before 14:00 local time (19:00 GMT) on Sunday after departing from Luis Muñoz Marín International Airport in San Juan, Puerto Rico. The flight also hit several vehicles on the ground.
Amazon said that it is "working closely with local authorities and officials to understand exactly what happened".
All flights were ordered grounded by the Federal Aviation Administration (FAA) as fire crews raced to the smoking crash site. The crash comes over Labor Day weekend, one of the busiest travel times of the year.
It is not yet clear whether those who died were in the plane, on the ground, or both.
"At least five people have lost their lives, and five others are injured," Miami-Dade County Mayor Daniella Levine Cava said at a news conference on Sunday evening.
She added that rescue crews arrived at the scene within "seconds" of the crash.
"Right now, our focus is on the families, those who were injured, and the ongoing response," she continued.
Three of the five people injured are in critical condition, said Miami Fire Chief Raied Jadallah. The mayor said they were all taken to hospital with "unknown injuries".
Several of the injured were trapped inside or under vehicles on the ground, and needed to be extricated by fire and rescue crews, said Jadallah.
Officials say it is too early to know the cause of the crash, and that it will be investigated by the National Transportation Safety Board. The federal agency, which investigates all air crashes in the US, plans to hold a news conference on Monday.
The Amazon flight operated by 21 Air, a charter company based in North Carolina, "overran Miami International Airport's diagonal runway and is disabled at the northwest end of the airport," the airport said in a statement.
Miami Dade Fire Rescue said crews "arrived to find an airplane that had caught on fire as a result of this crash, with heavy flames and smoke showing".
Over 200 firefighters responded to the crash. The flames were extinguished, but there was still a fuel leak at the site, said Jadallah.
Locals described the aftermath of the incident. One woman, Beth Tilman, told the New York Times said she had seen a black cloud where the plane had crashed, and had smelled an acrid stench.
"It wasn't trees burning. It wasn't mangroves burning. It was some other odour that I, honestly, had never smelled before," she said.
A student pilot, Rohan Ellis, told the same newspaper he had witnessed sirens and helicopters overhead when he arrived at the scene of the crash. Describing what had happened to the vehicles that the plane had hit, he said: "They were mangled."
Amazon issued a statement saying that it was working closely with authorities and offering condolences to the victims.
"We're heartbroken to learn that five people lost their lives in today's incident at Miami International Airport," said Kelly Nantel, Amazon's Director of Corporate Global Media Relations.
"Our deepest sympathies go out to the families, loved ones, and all those affected by this devastating loss.
"The airplane, which was operated by 21 Air, was attempting to land when this incident occurred. We're working closely with local authorities and officials to learn more and will cooperate fully with any investigation."
