A person in a car was the seventh fatal victim of the fiery crash of an air ambulance onto a busy Philadelphia street, authorities said Saturday, as investigators sifted through burned cars, damaged homes and charred debris for clues to determine why the aircraft plummeted shortly after takeoff.

Carrying six people from Mexico, including a child who spent months in treatment at a hospital, the Learjet 55 went down just after departing from the Northeast Philadelphia Airport, creating what witnesses described as a massive fireball, shaking houses and leaving a chaotic street scene.

Authorities couldn’t yet say why the jet crashed, and Adam Thiel, the city’s managing director, said it could be days — or longer — until officials are able to fully count the number of dead and injured across a sprawling impact area in a densely populated residential area.

The plane took off, reached about 1,500 feet of altitude and then plummeted in a steep descent, crashing less than a minute after takeoff in what National Transportation Safety Board chair Jennifer Homendy called a “high-impact crash” that left the plane “highly fragmented.”

Seven dead and 19 hurt, although the toll could go higher

As of Saturday morning, officials said, there were seven dead — six on the jet and the person in the car — and 19 injured. Most of the injured had been treated and released, hospitals said.

There are “a lot of unknowns about who was where on the streets” when the plane crashed, and it is possible that the casualty figures will grow, Thiel said.

The crash scene was at least four to six blocks, and authorities were working to assess the damage, including going house to house to inspect the dwellings, Thiel said.

Homendy said her agency’s staff was working to collect debris from the plane, which could take days or weeks, and haul it away to a secure location to begin evaluating it.

Air traffic controllers didn’t hear anything concerning before the crash, and her agency was still looking for the cockpit voice recorder, a helpful piece of evidence in the investigation, Homendy said.

It is likely damaged and possibly fragmented because of the impact, although her agency’s researchers and engineers have significant expertise in repairing them, she said.

The plane hit the ground just after 6 p.m., during a busy Friday evening dinner hour less than 3 miles (5 kilometers) from the airport.

“All of sudden I heard like a ‘boom,’ and I thought it was a thunderstorm,” said Selkuc Koc, a waiter at the Four Seasons Diner on Cottman Avenue. “And I get up and look at the smoke and the fire, it was like a balloon. I thought it was a gas station that blew up.”

One diner patron was hit and injured by a small but heavy metal object that flew through the window, Koc said.

Child patient had just finished treatment for life-threatening condition

Of the six people on board the medical transport jet, one was a child who had just completed treatment at Shriners Children’s Philadelphia hospital, one was her mother and four were crew members, officials said.

A hospital spokesperson said the girl spent four months there receiving life-saving treatment for a condition not easily treated in Mexico. Shriners officials said they couldn’t give details about the girl or her family because of patient privacy rules.

“Her journey was one of hope and of aspiration,” spokesperson Mel Bower told The Philadelphia Inquirer. The relationships that the girl formed with staff “were true and were dear,” and she’ll be missed greatly by them, he said.

All the victims on the jet were from Mexico

Mexican President Claudia Sheinbaum said all six victims on the plane were from her country. In a statement on the social media platform X, she mourned their deaths.

“Consular authorities are in constant contact with the families; I have asked the Foreign Affairs Secretary to support whatever is needed. My solidarity with their loved ones and friends,” she said in Spanish.

Tijuana, Mexico, across the border from San Diego, was to have been the flight’s final destination after a stop in Missouri.

Neither Philadelphia officials nor plane owner Jet Rescue Air Ambulance disclosed the identities of the dead.

But XE Médica Ambulancias, a Mexican emergency service, identified one of its doctors, Raúl Meza, as a victim. In a post on X, it said he was the service’s chief of neonatology and assigned to a the ISEM Atizapán hospital, which is in the State of Mexico near Mexico City.

In Veracruz, a city on the Gulf of Mexico, relatives of Josué Juárez said he was the aircraft’s co-pilot. They were preparing to hold a family ceremony and staying away from TV and social media to avoid seeing images of the crash.

They hadn’t seen videos, but they were told that there was a horrible explosion, that the plane broke apart and that the crash scene covered several blocks, brother Édgar Juárez told The Associated Press by phone.

Josué Juárez, 43, lived in central Mexico, loved salsa dancing and video games and had been a pilot for more than a decade, his brother said. He loved to fly and worked for the air ambulance service for more than a year, flying mostly from Mexico’s Caribbean coast to the United States.

“He was always aware that he had his risks, but the truth is that more accidents happen on the road,” Édgar Juárez said.

Crash comes on the heels of devastating D.C. midair collision

The crash came just two days after the deadliest U.S. air disaster in a generation. On Wednesday night, an American Airlines jet carrying 60 passengers and four crew members collided in midair in Washington, D.C., with an Army helicopter carrying three soldiers. There were no survivors.

Homendy said the NTSB is a highly skilled agency, and that it is not unusual for it to investigate two major accidents at the same time.

Jet Rescue Air Ambulance, which operated the Mexico-registered Learjet 55, is based in that country and has operations both there and in Miami. A company spokesperson said a seasoned crew operated the plane, and all flight crews undergo rigorous training.

The Philadelphia crash was the second fatal incident in 15 months for Jet Rescue. In 2023 five crew members were killed when their plane overran a runway in the central Mexican state of Morelos and crashed into a hillside.

Air traffic controller lost contact with Learjet

The Learjet took off from Northeast Philadelphia Airport, which primarily serves business jets and charter flights.

Audio recorded by LiveATC captured an air traffic controller telling “Medevac Medservice 056” to turn right when departing. About 30 seconds later, the controller repeats the request before asking, “You on frequency?” Minutes later the controller says, “We have a lost aircraft. We’re not exactly sure what happened, so we’re trying to figure it out. For now the field is going to be closed.”

Michael Schiavone was sitting at his home nearby when he heard a loud bang and the house shook.

“There was a large explosion, so I thought we were under attack for a second,” he said.

A doorbell camera captured video of the plane plunging in a streak of white and exploding as it hit the ground.

“All we heard was a loud roar and didn’t know where it was coming from,” said Jim Quinn, the doorbell’s owner. “We just turned around and saw the big plume.”