Steven Chealander, a National Transportation Safety Board member, said the agency wouldn't speculate on a cause until the investigation is complete, which could take up to a year.
Investigators will examine the weather, the background of the pilots, the plane's condition, witness accounts and air controller traffic prior to the crash.
"We are in the evidence-gathering stage of this investigation," Chealander said in a briefing to reporters.
The cockpit voice recorder was recovered Thursday and sent to the NTSB lab in Washington for analysis, along with a flight management system, a device that contains data but is less elaborate than the flight data recorders on large jets.
The jet was carrying six casino and construction executives and two pilots when the plane went down, killing all aboard. The executives were coming to Owatonna to meet with representatives of a local glass company called Viracon to discuss a $2 billion hotel-casino complex being built in Atlantic City by Revel Entertainment.
The charter jet went down in a cornfield northwest of Degner Regional Airport. The airport was closed to arriving planes Friday.
The only flights allowed were departures, and those aircraft were forbidden to fly over the crash site.
Roy Redman, president of RARE Aircraft Inc., a mechanics company at the airport, said Friday that he was inside and heard the plane land on the runway. Moments later, one of his mechanics who had watched the landing came running around the building, yelling that the jet had gone off the runway and disappeared in some trees in the distance.
Redman, who called 911, said the mechanic told him the jet landed, then went airborne, rolled and hit the ground.
Doug Neville, Department of Public Safety spokesman, said the airport has no control tower, and pilots communicate with controllers in Minneapolis.
An hour before the crash, a 72 mph wind gust was reported in Owatonna, according to the National Weather Service. But witnesses said the crash occurred after the worst of the storm had passed, with the sky clearing and only light rain.
Seven people were found dead at the site. One died later at a hospital.
The victims were identified as: - Tony Craig, 50, and Chris Daul, 44, both vice presidents of construction development at Revel Entertainment; and Lawrence Merrigan, 62, the company's director of field operations.
- Karen Sandland, 44, a project manager for Tishman Construction Corp. who was working on the Revel project.
- Two executives of APG International, a New Jersey company that specializes in glass facades: Marc Rosenberg, chief operating officer, and Alan Barnett, assistant project manager.
- Two pilots for Allentown, Pa.-based East Coast Jets, Dan D'Ambrosio, 27, and Clark Keefer. The company declined to comment on the pilots' background Friday.
Two other people who were supposed to be on board did not get on the flight, Neville said.
Gambling and construction executives working to build a new $2 billion mega-casino here were among the eight victims of a plane crash in Minnesota on Thursday.
The morning crash that killed employees of Revel Entertainment Inc. and Tishman Construction recalled a similar tragedy in 1989, when three of Donald Trump's top executives died as their helicopter crashed in a wooded median strip on the Garden State Parkway about 35 miles north of Atlantic City.
Karen Sandland, 44, a project manager on the Revel casino project who worked out of Tishman Construction's Newark, N.J. office, was killed in the crash, company spokesman Bud Perrone said.
Also killed were two pilots, Clark Keefer of Bethlehem, Pa. and Dan D'Ambrosio of Hellertown, Pa., according to Brad Cole, president of East Coast Jets, the company which owned the plane.
"We want to express, on behalf of all East Coast Jets employees, our determination to attend to the needs of everyone involved in this tragic event," he said.
Daniel R. Tishman, chairman & CEO of Tishman Construction, said his company was praying for the victims.
"Our hearts go out to everyone who has been affected by this tragedy," he said.
Sandland was the only Tishman employee aboard the plane, said Richard M. Kielar, the company's senior vice president.
Atlantic City Mayor Scott Evans said two high-ranking Revel executives also were among the victims, but neither Evans nor the company would immediately identify them, citing the need to notify relatives.
Revel CEO Kevin DeSanctis issued a statement Thursday night mourning the loss of employees, but did not say how many were killed or identify them.
"Everyone at Revel Entertainment is deeply saddened by today's tragedy," he said. "The loss of Revel executives and our partners from Tishman Construction and APG is a heartbreak to all on the team. The thoughts and prayers of our entire organization are with the family and friends of today's victims."
DeSanctis was referring to APG International, a Glassboro, N.J. company that specializes in glass facades, which lost at least one employee in the crash.
APG's telephone rang unanswered Thursday night, and no one immediately responded to a fax and an e-mail seeking comment that was sent to their office.
The Revel and Tishman workers boarded a Raytheon Hawker 800 at Atlantic City International Airport at 7:10 a.m. Thursday after the plane flew from its base in Allentown, Pa.
The plane needed no services at the Atlantic City airport, and took off again at 8:13 a.m. bound for Minnesota, where the occupants were to attend a meeting at a glass company. The plane then crashed in bad weather at a regional airport in Owatonna, a town of 25,000 about 60 miles south of the Twin Cities of Minneapolis and Saint Paul.
The employees were headed to a meeting at Viracon Inc., an Owatonna-based company that earlier this year was awarded a contract to supply glass to the World Trade Center site. Viracon also is providing glass for the facade of the Revel casino, and it was this project that the Atlantic City executives were traveling to Minnesota to discuss, said Kielar, the Tishman senior vice president.
The crash instantly brought back memories of the Trump helicopter crash on Oct. 10, 1989.
Killed were Stephen F. Hyde, 43, chief executive of the three Trump casinos; Mark Grossinger Etess, 38, president and chief operating officer of the Trump Taj Mahal Casino Resort, and Jonathan Benanav, 33, executive vice president of Trump Plaza. Also killed were the pilot and co-pilot.
"It was very bad; they were my top people," Trump recalled on Thursday. "It shows the hazards of flying and the hazards of life, and there's nothing you can do about either. You have to get the best equipment and the best pilots, and even then you need a lot of luck."
Daniel Heneghan, a spokesman for the New Jersey Casino Control Commission, recalled how the deaths devastated not only Trump's company, which was preparing to open its flagship Taj Mahal, but the entire industry.
"It was a shocking blow to everyone here, to see three very vibrant people with such a great mixture of talent, leadership and marketing skills lost like that in their prime so suddenly," he said. "It made you remember how fragile life is, and today's tragedy is doing the same thing."
Revel Entertainment is building a $2 billion ocean-themed casino on the Atlantic City Boardwalk. Called simply "Revel," it consists of a hotel-casino designed to appear that its eastern facade were sculpted by the waves rolling in from the Atlantic.
The first phase of the project calls for a single tower with 1,800 to 1,900 rooms. When a second tower is built, that number would rise to 3,800 to 3,900 rooms.
It will offer 150,000 square feet of casino space, and 500,000 square feet of dining, retail and entertainment space, including Atlantic City's first casino wedding chapel. It had been on track to open in late 2010, but it could not be determined if the executives' deaths would affect that timetable. --- Associated Press writer Wayne Parry in Atlantic City, N.J., contributed to this report.
(Copyright 2008 by The Associated Press. All Rights Reserved.) AP-NY-08-01-08 1429EDT
