An Amazon cargo plane barreled off a runway at Miami International Airport on Sunday, killing at least five people and injuring five others as it struck vehicles and was engulfed in flames, authorities said.

The aircraft overran the runway around 2 p.m. after arriving from San Juan, Puerto Rico, and plowed across a road used by warehouse workers and other businesses that surround the airport. Five people were killed, three critically injured and two others hospitalized with less severe injuries, Miami-Dade County officials told a news conference.

It wasn’t immediately clear if the pilots survived or those killed were all in vehicles when the plane struck.

The crash, which sent thick black smoke billowing into the sky, trapped the pilot and copilot in the cockpit and some occupants in cars, said Miami-Dade Rescue Fire Chief Ray Jadallah. The agency said crews also had to extricate a person who was trapped under a vehicle.

The crash halted flights at the busy travel hub for much of the afternoon. Some 200 emergency personnel responded, finding the plane with heavy flames and smoke from a complex engine compartment fire, the department said. Firefighters used foam from specialized airport firefighting units to extinguish the fire, and crews were still dealing with a fuel leak on the plane hours later.

The Prime Air plane came to rest beside a roadway near two semitrucks, images showed. The aircraft appeared to be resting on its belly and was largely intact despite the fire.

The cause had yet to be determined, and it was not clear if weather had played a role. Thunderstorms and wind gusts up to 30 mph (48 kph) were recorded in the area at the time, according to the National Weather Service.

The flight had been operated by 21 Air, a cargo carrier based in North Carolina. The 32-year-old Boeing 767 was originally built to carry passengers and flew for several airlines for more than two decades before being converted to a cargo plane in 2015, according to flight-tracking site Flightradar24.

More than 160 flights were canceled and nearly 325 delayed by late Sunday, according to FlightAware, a website that tracks flight disruptions. Officials from Orlando International Airport, more than 200 miles (320 km) north of Miami, said some flights were diverted there.

The National Transportation Safety Board said it was sending a team to Miami led by Chairwoman Jennifer Homendy to investigate.

Amazon said in a statement that it would cooperate with any investigation.

“We’re heartbroken to learn that five people lost their lives in today’s incident at Miami International Airport,” the company said. “Our deepest sympathies go out to the families, loved ones, and all those affected by this devastating loss.”