(CNN) Roberta Porter was driving with her grandson through Akron, Ohio, when a plane "dropped out of the sky." It slammed into an apartment building, causing an "instant boom and flames and smoke."

There was no one inside the four-unit apartment building when the small Hawker 700 plane smashed into it Tuesday, the Ohio State Highway Patrol said. That means no deaths or injuries on the ground, despite the jarring crash and massive fire that followed.

Nine people -- seven passengers and two crew members -- died in the crash, said Bella Dinh-Zarr, vice chairwoman with the National Transportation Safety Board, which is investigating the crash.

This includes the pilot and co-pilot on the jet operated by ExecuFlight, a Florida company, plus "two principals and five employees" of Florida-based real estate company Pebb Enterprises.

"We are shocked and deeply saddened for the families, colleagues and friends of those who perished," Pebb Enterprises said on its website . "Our first priority is to give our fullest support to the family members and loved ones of our co-workers."

Jeannie Ferrera said her younger sister was one of those Pebb Enterprises employees. She told CNN affiliate WEWS that she learned the news from her nephew, who got a call from Pebb on Tuesday night.

"I'm just in shock and in disbelief," Ferrera said. "And we just want to know what happened. ... We want some answers."

ExecuFlight President, Augusto "Danny" Lewkowicz was similarly "perplexed" and crestfallen about the loss of the two crew members, who'd been flying together at his company for about a year.

"You can't really prepare for this kind of stuff," he said. "This is the lottery ticket that nobody wants."

Big boom, followed by a sound like fireworks

Having set off from Dayton, the Hawker twin-engine, 10-passenger plane was approaching Akron Fulton International Airport when it crashed roughly two miles from the runway.

JUST WATCHED Surveillance video shows Ohio plane crash Replay More Videos ... MUST WATCH Surveillance video shows Ohio plane crash 01:09

The NTSB has security camera footage that shows the seconds leading up to the crash, Dinh-Zarr said.

It shows the jet was flying very low, descending and banked to the left. The left wing hit the ground, leaving a mark as the plane smashed into the apartments.

A man who worked in an office about a block away from the accident told WOIO he heard the crash but didn't see it.

Scott Ferrell said he could tell something had gone horribly wrong when he heard a plane engine cut out, fire up again, then cut out again.

"And probably a second later, I heard the explosion," Ferrell told the station. "(Then) there were power lives down everywhere. It was pretty chaotic (and) surreal."

The plane clipped power lines before it went through the apartment building. Video of the aftermath showed a huge fireball engulfing the building -- and touching nearby power lines and possibly structures on either side -- as black smoke billowed above.

The smoke cleared to reveal the bulk of the plane in an embankment behind the building.

"The fuselage, the passenger compartment, is somewhat intact," Haymaker said. "... It is heavily burned, and that's (where) lies the problem."

Dinh-Zarr said the pilot was using instruments to land and didn't make a distress call. CNN affiliate WJW of Cleveland reported that there was rain and low clouds in the area.

NTSB investigators have interviewed a pilot who landed just ahead of the flight and might speak with him again about the conditions on approach.

The cockpit voice recorder from the crash was sent to an NTSB lab in Washington.

Apartment tenant: 'I lost everything'

While experts from the Federal Aviation Administration and NTSB investigate what brought the plane down, firefighters were on site starting the recovery process, Akron fire Lt. Sierjie Lash said.

Lewkowicz, from ExecuFlight, said that the aircraft was in good condition and well-maintained, and that both crew members were experienced.

"We don't know what happened," he said. "But we know that we will know what happened soon. ... Planes generally don't fall out of the sky."

Dr. Lisa Kohler, the Summit County medical examiner, told reporters that her office will use its "mass fatality plan," given the scope of the tragedy. She said victims' names won't be released until each person is identified and their families are notified.

"This is a very complex situation," she said. "And it needs to be done very carefully, and it needs to be documented as well."

Haymaker, from the State Highway Patrol, said late Tuesday that a top priority is getting the right information out to the loved ones of those on the plane.

Then there is the struggle for those in Akron whose lives have been turned upside down by the crash. They include those who lived in the building hit directly, as well as the occupants of eight apartment units in the two buildings on either side.

The Red Cross has stepped up to offer food, clothing, hotel rooms and other assistance to those affected, such as Beth Montgomery, whose home is now just a shell.

"I was just in shock, and I was crying and upset," she told WEWS of her feelings when she learned about the crash.

"I lost everything."