WASHINGTON – Federal investigators will try to determine why a small plane catapulted into a Gaithersburg, Maryland, home as it crashed, killing three people in the plane and three in the home Monday.

The victims

The dead have been identified as 36-year-old Marie Gemmell and her two sons, 3-year-old Cole and 7-week-old Devin, police say.

Gemmell tried to protect the children from the smoke and fire, but there was nothing she could do, Montgomery County police spokesman Capt. Paul Starks said. Her body was found in a second-floor bathroom, lying on top of her sons.

“This is a tragic loss for the Montgomery County community,” says Montgomery County Fire Chief Steve Lohr said.

They are survived by the woman’s husband and a 5-year-old daughter who was at school at the time of the accident, officials says.

A GoFundMe account has been started by a friend of the Gemmells to help with funeral and other expenses. BY 3 a.m. Wednesday, it had raised just under $300,000.

Click to donate to the Gemmell Family Fundraiser

Of the three people killed on the plane, two have been identified. The third was tentatively identified.

One was Dr. Michael Rosenberg, founder and CEO of Health Decisions, a clinical research organization in Durham, North Carolina. Rosenberg was piloting a plane that crashed in Gaithersburg on March 1, 2010.

“Everyone at Health Decisions is devastated by the loss of our friend and colleague Michael Rosenberg,” Health Decisions Vice President of Clinical Affairs Patrick Phillips said in a statement. “The thoughts of the management and employees of Health Decisions go out to Dr. Rosenberg’s family as well as to the families of the other passengers.”

Dr. David Hartman of Nuventra Pharma Sciences in North Carolina also died. Hartman was a scientist who developed drugs with an expertise in drug metabolism.

In a statement, Geoffrey Banks, CEO of Nuventra Pharma Sciences writes, “We are deeply saddened by the loss of David and will miss him both personally and professionally.”

Montgomery County police are investigating the deaths.

Chikioke Ogbuka, 31, of Raleigh, North Carolina, was tentatively identified on Tuesday as the third victim.

Crash

The twin-engine plane, a Embraer EMB-500/Phenom 100, went down on Drop Forge Lane, less than a mile from the Montgomery County Airpark at 10:44 a.m., damaging three homes.

The Gemmell home was gutted by the crash and ensuing blaze. The first floor was nearly completely blown out. No one was injured in the two adjacent homes that also had major damage.

It took firefighters several hours to shore up the destroyed house in order to search the upper levels where the family was found, Montgomery County Fire Chief Steve Lohr said.

The jet’s fuselage crashed into the front lawn of a home adjacent to the Gemmell’s, which was heavily damaged by fire, and investigators believe one of its wings, which had fuel inside, sheared off and tore through the front of the Gemmell home, said Robert Sumwalt, a National Transportation Safety Board member. Witnesses reported seeing and hearing a secondary explosion after the plane hit the ground.

The Embraer 500 was traveling from Chapel Hill, North Carolina, to Montgomery County and was making an instrument-guided approach to land at the Montgomery County Airpark at the time of the crash.

Near the airfield along a small cul-de-sac of homes, investigators found a narrow gash through the roof of one house. Part of the fuselage came to rest against a second house with the tail of the plane landing in front of that house. One wing catapulted into the third house, which suffered the brunt of the fire damage and which was where the mother and children were found, Sumwalt says.

Wings carry fuel, which could have triggered the fire, he says.

Investigation

National Transportation Safety Board investigators will spend the next week or so gathering evidence at the scene.

“Our mission is to find out not only what happened but why it happened because we want to make sure something like this never happens again,” Sumult says.

Investigators will try to determine whether Rosenberg was at the controls at the time of Monday’s crash.

They have recovered the the cockpit voice and flight data recorders, which were rushed to D.C. for analysis, says spokesman Sumwalt.

During the NTSB review, investigators will look at the plane’s engine and flight controls, weather, radar and communication with air traffic controllers and other aircraft using the field as they reconstruct the crash.

The agency planned to look into everything that could have led to the crash, including crew experience and proficiency, training and procedures, equipment performance, weather and other environmental factors, Sumwalt said.

Among the possibilities investigators will consider is whether a flock of birds contributed to the crash.

“That is one of the many things that we will look at. So I’ll put it to you this way, nothing is off the table, everything is on the table,” Sumwalt says.

After the investigators gather information, they will determine the cause of the crash.

Area residents have been given the OK to return to their undamaged homes, but have been told that the investigation will restrict access to their neighborhood.

Snouffer School Road, which had been closed, reopened Tuesday morning.

Witnesses

While it’s too soon to know what went wrong, several eyewitnesses tell WTOP that the plane appeared to be struggling before it went down. The initial 911 call reported an explosion and a building fire.

Vaughn Smith tells WTOP he was waiting at the light at Lewisbury Park and Snouffer School Road when the plane went down.

Smith says the brightly colored blue-and-white plane was struggling back and forth.

The plane was about 100 feet from Smith’s vehicle and about 50 feet off the ground when it went by him, tipping its wings.

“It had crashed into a house, and the house was engulfed in flames,” Smith says. “I called 911, and they didn’t quite know about it yet.”

Witness Larry Matthews tells WTOP that the plane “was making strange noises, like the engines weren’t fully functioning.”

“It was flying very erratically. It was kind of left and right. Its wings were dipping, and it appeared to me to be out of control,” Matthews says.

“This guy, when I saw him, for a fast jet with the wheels down, I said, ‘I think he’s coming in too low,'” Fred Pedreira, 67, who lives near the crash site, told The Associated Press. “Then he was 90 degrees — sideways — and then he went belly-up into the house and it was a ball of fire. It was terrible.

“I tell you, I got goosebumps when I saw it,” Pedreira said. “I said, ‘My God, those are people in that plane.'”

The Associated Press contributed to this report. Follow @WTOP on Twitter and on WTOP Facebook page.