Investigators with the National Transportation Safety Board plan to remove a crashed plane Tuesday evening that killed four people from Connecticut. The flight was returning from Vermont when it went down Sunday afternoon.

A 15 year-old taking flying lessons died, along with her mother and one of her teachers, at Middletown High School.

According to a preliminary investigation, the single engine Piper went down around 12:25 p.m. Sunday, just south of the runway at Basin Harbor Airport, a small airstrip near Ferrisburgh, Vermont.

NTSB investigator Kurt Gibson said that type of aircraft does not have a “black box,” but some instrumentation might still contain clues about what went wrong.

“We will also be looking at the pilot, his qualifications, and getting a 72-hour history of him,” Gibson said at an afternoon news briefing. “And we’ll also be looking at the environment, the weather and [Air Traffic Control] involvement, the runway itself.”

Gibson said the NTSB plans to move the aircraft to a salvage facility on Tuesday evening.

The crash killed Delilah Van Ness, a sophomore at Middletown High, and Paul Pelletier, her aviation teacher at the school. Pelletier had been giving Van Ness flight lessons, but Gibson indicated that a male was at the controls when the Piper went down.

Van Ness’ mother, Susan, was also killed. She worked for the National Diaper Bank Network. The final victim was Frank Rodriguez, an 88 year-old former U.S. Air Force pilot along for the ride.

The flight left Windham Airport in northeastern Connecticut on Sunday morning. All four had flown to a resort on Lake Champlain for brunch, but never arrived back in Connecticut that night. After relatives contacted police, search crews located the wreckage nearly 12 hours after the plane went down.

Online flight records show no prior incidents with the plane.

Middletown High School was closed on Tuesday. Instead, grief counselors were available and vigil was held for the victims.