An executive jet crashed into a Gaithersburg house Monday, killing all three people aboard the plane and a woman and her two children inside the house, authorities said.
The victims inside the house were identified as Marie Gemmell, 36, and her two sons, 3-year-old Cole Gemmell and Devon Gemmell, an infant. They were found together on the second floor of the house.
"She tried to save these kids," Montgomery County Police Chief Thomas Manger said. "She had nowhere to go. She couldn't get out of the bathroom. One kid was between her legs, and the other was in her arms."
Pete Piringer, a spokesman for the Montgomery County Fire and Rescue Department, said the three victims aboard the plane were found dead at the scene. The crash killed pilot Michael Rosenberg and the two other people on board, Piringer said on Twitter. The other two people in the plane were not identified.
Monday's crash happened about 11 a.m. as the plane neared the Montgomery County Airpark.
According to the Federal Aviation Administration, the Embraer SA twin-engine Phenom 100 jet was registered to Rosenberg, an adjunct professor of epidemiology at University of North Carolina, Chapel Hill and CEO of clinical research company Health Decisions, Inc.
Rosenberg had previously crashed a plane destined for the same airport in 2010, according to records.
There were no injuries in Rosenberg's 2010 crash, according to National Transportation Safety Board records. The 2010 accident occurred when he lost control while landing and crashed into trees, according to records.
Monday's crash sparked a fire that destroyed two homes, and three others were damaged. Piringer said crews had contained the fires but some jet fuel had leaked into a stream.
The plane had departed from an airport in Chapel Hill at 9:30 a.m., an NTSB spokesman said at a news conference Monday night.
Investigators, who were expected to be on the scene for up to seven days, will examine the experience and training of the pilot, weather factors and engine condition, and interview the aircraft controller who handled the attempted landing, NTSB spokesman Robert Sumwalt said. They will also look into a possible bird strike.
"Our mission is to find out what happened, and why it happened, so it will never happen again," Sumwalt said.
Sumwalt said the plane cut a narrow gash through the roof of one house, slicing into what appeared to be a bedroom. Much of the plane came to rest against a second house. A wing, which contained fuel, catapulted into the third house, where the fire started, killing the three residents.
Police said that the cause of death for the victims in the house may have been smoke inhalation but that it remained under investigation.
Neighbors in the area said the young children often played outside and that the family was known to be friendly and hosted neighborhood get-togethers.
"I'm sad, so sad," said Marlon Cienfuegos, who has lived in the neighborhood for about 15 years. "You don't want this to ever happen, and this time of year — it's terrible."
Dianne Gayle, who also lives on the street, said she was working Monday morning at her home, heard a plane overhead and at first thought it wasn't a big deal. Then, she said, she heard a boom and saw flames. She said she called 911 immediately and recalled saying to the dispatcher: "The house is on fire! The house is on fire! A plane crashed into the house! A plane crashed into the house!"
"It's just heartbreaking," she said.
Authorities said the plane reportedly had turned on final approach to land at the nearby airpark, just behind a Cessna 172 propeller-driven plane.
The county-owned airport opened in 1959 to relieve aviation traffic into what is now known as Reagan National Airport. Since the emergence of Baltimore-Washington International Thurgood Marshall Airport and Dulles International Airport, the facility in Gaithersburg has transformed into one used by small planes and business travelers.
The airport has about 100,000 annual departures and arrivals and is the fourth-busiest general aviation airport in Maryland.
There have been 12 crashes at Gaithersburg since 1996, none of them fatal.
Reuters and The Washington Post contributed to this article.