OKLAHOMA CITY -- An aircraft went down on the Northwest Expressway near Candlewood Drive around 9:00 a.m., killing one man.

Five passengers were in the aircraft including the pilot, Ron Meyer. Officials with the OU Medical Center said Meyer has died. His wife, Nam Meyer, along with three other passengers, including retired Oklahoma County Sheriff's deputy Greg Compton and two other females were taken to a hospital in serious condition.

Nam is currently listed in fair condition. Compton is currently in critical condition. Compton's wife and his niece were the other two passengers on the aircraft. Their names and conditions have not been released.

Officials said the single engine Beech Bonanza plane may have been having engine problems after taking off from Wiley Post Airport.

The single-engine plane was apparently trying to make an emergency landing when it clipped a tree and crashed in front of a Bank of Oklahoma along Northwest Expressway.

An EMSA crew was in the area, witnessed the crash and quickly began treating those on board.

"Within two, three minutes we were treating those patients with extractions from the plane craft and taken to the hospital," said Chris Prutzman, EMSA Operation Supervisor.

Emergency officials said the situation could've been a lot worse if the plane landed on the street rather than the side of the road.

"If they had attempted to land on Northwest Expressway, with the type traffic flow that's on Northwest Expressway, there would be a lot more injuries on the ground. But in this case they landed on shoulder. They did clip some trees, which caused them to spin around, but they did land with the belly down, which was the best possible orientation that they can land in," said Oklahoma City Fire Battalion Chief Steve Lumry.

FAA and investigators are looking into exactly why the plane was forced to make an emergency landing.

Westbound lanes of Northwest Expressway were shut down Saturday while officials investigated the crash.

Ron Meyer was the owner of Phoenix Fabrication, LLC in Oklahoma City. Meyer and his wife had plans to adopt a little girl from Vietnam.