A grandfather and three of his grandchildren, all Israeli citizens, were killed yesterday when a small plane crashed in northern Michigan.

A fourth grandchild was seriously injured.

The plane, which crashed near the town of Saint Ignace, reportedly reached an altitude of only 300 meters before it struck a highway median, flipped over and burned.

The grandfather, 73-year-old Moshe Menora, a Chicago-area resident and a pilot with 30 years' experience was killed instantly, along with his granddaughters, Rivka Menora, 16, and Rachel Menora, 14, of Beit Shemesh and Sarah Klein, 17, of Har Nof in Jerusalem.

A grandson, Yossi Menora, 13, is suffering from severe burns covering 50 percent of his body and has been placed in an induced coma. On arrival at the hospital, he said he had been sitting in the seat furthest to the rear of the six-seater plane and had been asleep when the crash occured.

He was thrown from the plane after it broke apart.

The ZAKA search and rescue organization assisted in the retrieval of the bodies, while the Israeli Consulate in Chicago is making arrangements to fly the bodies back to Israel for the funerals next week.

Local police said the plane had encountered "some form of difficulty" during takeoff from a field where they had landed to refuel.

The U.S. Federal Aviation Authority and the National Transportation Safety Board have launched an investigation into the crash. As the victims are Israeli citizens, a representative of Israel's Transportation Ministry can act as an observer on the American investigation team.

Moshe Menora, who was in the real estate business, was born in Haifa and lived in Skokie, Illinois, where he was considered a pillar of the local Orthodox community.

Menora's widow, Sema, told reporters she had expected her husband and grandchildren to return at around 5:30 P.M. after their day's outing. "All I said was 'Enjoy yourselves and see you at dinner,'" she said.

The grandchildren had gone to the United States with their father, Sholom Menora, for a family wedding.

"I got a call at 6 P.M. from the hospital... They told me there had been a plane crash and that [Yossi] was seriously injured. I asked about the other passengers and they said no one else had survived," Sholom Menora said, speaking from his son's hospital bed. "It's ironic. I have two sons in the army... and I always worry about them. I can't believe something like this could happen to my daughters while flying with my father."

"We had a fun day the day before," said Sholom Menora, who is in the Internet business. "We went to a museum and I took the last picture of the three of them together. I shut off my phones and we just had fun together. Then I told my father, 'You take them on a trip and I'll go to work.'"

Another grandson, Yehuda Menora, who did not go on the trip because he is in the army, said: "Every time we went to the States, we would fly with [our grandfather]. I was never scared. I loved flying with him. It's safe to assume that if I were there, I would have been on that plane," he said.

Sholom Menora said one of the plane's controls had malfunctioned, but a crash expert in Israel told Haaretz yesterday that human error cannot be ruled out.

"It is still too early to say what happened, but I suppose that it is less a technical matter, because if there were a problem, the pilot would have seen it and not attempted to take off," the expert surmised.

The expert said that the pilot's age, while considered relatively advanced for still-active pilots, was not necessarily a factor due to his extensive flying experience.