Witnesses to a fiery, peak hour plane crash beside one of Melbourne's busiest freeways have told of a "massive fireball" after the light aircraft plummeted.
The charter plane crashed into the Spotlight store at Essendon's Direct Factory Outlet shortly after takeoff at 9am.
Five people have been confirmed to be on board.
A taxi passenger, Jason, told ABC Radio Melbourne he was travelling along the Tullamarine Freeway, which borders Essendon Airfield, when he looked out the window and saw what he thought was a twin-propeller plane.
"I saw this plane coming in really low and fast. It went just behind the barriers so I couldn't see the impact but when it hit the building there was a massive fireball," he said.
"I could feel the heat through the window of the taxi, and then a wheel, it looked like a plane wheel, bounced on the road and hit the front of the taxi as we were driving along.
"We kept driving and there was big fireball behind us."
Angelo Taddis was working outside the complex when he heard a plane engine revving exceptionally loudly. When he looked to the sky, he saw the plane nose dive into the DFO.
He and a colleague rushed to the scene with fire hydrants but were powerless to help.
"It nosedived to the back of DFO and there was just a huge flame ball," Mr Taddis told Channel 7's The Morning Show program.
"I haven't really heard anything that loud and so low before. I hear planes taking off and landing every day, but this was just different."
"I was just at work and I heard the motors revving and as I've looked up a plane nosedived into the building at the back and as soon as that happened we've all run outside to see if we can give them a hand, you know, see what we can do. But there was nothing we could do," Mr Taddis added.
"The flames were just too big and too high. Within a couple of minutes the fire brigade and aviation people were on the scene. There was nothing you could do. It was pretty intense."
A cafe operator inside the complex told news.com.au the crash occurred at the rear of the complex's Spotlight store.
All staff have been accounted for.
A second business owner said she saw the crash from the freeway on her way to work.
"I actually saw the explosion. I was coming off the freeway and I saw this huge explosion," she said.
"There were flames coming out of the (DFO) roof and all this black smoke."
The business owner said the aircraft did not make it far.
She said the crash occurred right near the neighbouring Essendon Airport runway.
"They are not letting anyone in at the moment," she said.
"I haven't heard anything, so I'm just wondering whether to start up or not."
Emergency services have closed the shopping centre and are not allowing anyone to enter.
It is understood the five-person Beechcraft aircraft was a charter plane heading to King Island, in the Bass Strait.
Police, firefighters and paramedics have arrived at the Essendon airfield after the plane crashed about 9am on Tuesday.
A caller told 3AW there were "constant explosions" and black smoke billowing into the sky.
- additional reporting AAP