With Ha'aretz staff

Rescuers say they believe only a few bodies remain in the ruins of a Jerusalem wedding hall that collapsed on Thursday night, killing at least 26 people. But dozens of the people hospitalized after the accident are said to be in critical condition.

On Fridayt night Israel television reported that 183 people have been hospitalized for at least the weekend. The lightly-wounded among them will be released on Saturday night or Sunday morning.

Altogether about 350 people were reported wounded in the accident, which is being termed the worst disaster of its kind in Israel's history.

About 700 people had attended the ill-fated wedding between Asi and Keren Dror, which took place on the third floor of the Versailles Hall building. During the festivities the floor collapsed, plunging hundreds down three storeys.

The wedding video, broadcast on Israe TV, shows that the dance floor suddenly sank a few feet. Within a second or two it collapsed, breaking through the floors below. Most of the hundreds of people crowding the dance floor were trapped beneath concrete ruins.

The bride was among the badly injured. The groom was reportedly not injured.

Trained dog forces called in

Members of the Home Command special rescue teams, who have participated in earthquake rescue efforts such as the one in Turkey last year, were using specially-trained dogs Friday morning in an effort to detect signs of life among the ruins. Rescue workers were being accompanied by structural engineers to ensure that the remaining ceiling in the hall did not collapse on them. The rescue operation is expected to last several days.

Police quickly ruled out the possibility of a terrorist attack, saying the building almost certainly collapsed as a result of structural faults. "We are talking about a major disaster," said Jerusalem police chief Miki Levi, moments after arriving at the collapsed building onm Thursday. "Dozens are trapped under the ruins... it appears to have been caused by a serious engineering failure." It turns out to be that hundreds were trapped.

Police Commissioner Shlomo Aharonishki later confirmed that an "engineering fault" had almost certainly been the reason for the crumbling of the building. The owner of the three-storey wedding hall, which was built in 1986 and is located on Bethlehem Road, was detained Thursday night for questioning by the police, who also confirmed that renovation works had been undertaken in the building several days ago. The contractor who carried out the renovations and an engineer who had approved them, were also taken in for questioning.

According to the initial police investigation, the owner of the hall had insisted that the contractor remove several support beams in the building. An initial survey of the ruined building conducted by rescue workers revealed that four support beams had been removed during the renovations in order to enlarge the hall. The possibility that sub-standard materials had been used to construct the floor in the hall was also being checked.

The ceiling that collapsed - beneath the collapsed floor - had been made of Pal-Kal, a discredited technology, Israel TV reported on Friday night.

At a press conference Friday morning, Mayor of Jerusalem Ehud Olmert said that initial investigations seemed to indicate that there were grave defects in the construction and maintenance of the building. He noted that the municipality had not been made aware of these defects.

Major General Ofir said it was possible that survivors trapped under the rubble could be found for as long as a week after the collapse of the building. He called the incident "the greatest tragedy of its kind in Israel's history."

Television footage in the immediate aftermath of the disaster showed the building with a gaping hole down the middle. Hysterical guests, some of them with blood streaming from head wounds, could also be seen roaming amid the shattered concrete and twisted steel reinforcing bars.

Some 100 ambulances, many from the Tel Aviv area, made their way to Jerusalem to assist in evacuating the injured. The Jerusalem-Tel Aviv Highway was even closed temporarily to allow rescue vehicles to get to the site as quickly as possible. Magen David Adom ambulance teams treated many of the lightly injured at the site of the disaster due to the large number of more seriously injured flooding the city's hospitals.

One person attending the wedding, who was unhurt, said that he was sitting at a table when the dance-floor area suddenly gave way. Another guest, who plummeted several storeys with his 10-year-old son said, "I grabbed my son as the floor collapsed. We fell one floor, and then the next floor collapsed. And the next. And I'm trying to hold my son's hand all the time. We dropped all the way down. We were in the ruins. We had to be extracted."

After the floor collapsed, several people were left perched on ragged concrete platforms atop support beams, some 15 meters above the ground. Some of them lowered themselves down by tying together tablecloths.

"All the people were dancing and celebrating, and then suddenly there was a huge boom," said Malka Ben-Yehezkel, a wedding guest. "The whole floor collapsed. The table we were sitting at plummeted down and a couple sitting with us at the table went down with it. My daughter and I were left a distance of two floor tiles from the edge of where the floor gave way."