JERUSALEM - The Palestinian suicide bomber was already aboard the crowded commuter bus when 14-year-old Maor Kimche climbed on with his school bag and elbowed his way to the back.
Minutes later, as the green and white bus rolled to a stop on tree-shaded Mexico Street in the Kiryat Menahem neighborhood southwest of downtown, the militant triggered a powerful blast, killing himself and 11 passengers and wounding at least 40 others.
"Everything went black," Maor said from his bed at Hadassah Ein Kerem Hospital, as blood oozed through a gauze bandage covering a quarter-size hole in his left leg, just above the ankle. "I got up and jumped through a window."
Maor said he felt lucky to be alive. But his parents, Elana and Doran Kimche, knew they would have to tell their son that others had died in the blast and that one of his classmates was among them.
The Islamic Resistance Movement, known as Hamas, claimed responsibility for the attack, the 95th suicide bombing in Israel in the past 25 months. The attacker was identified as Nael Azmi Abu Hilail, 23, from a family of 13 in the West Bank village of el-Khader, situated on the outskirts of Bethlehem and just a 20-minute walk from the site of the bombing.
Kiryat Menahem is a modest, working-class section of Jerusalem where cars are a luxury and people rely on buses to get around. Passengers on the bus yesterday included high school students, soldiers and others off to jobs as clerks, garbage collectors and secretaries.
A 44-year-old mother and her 16-year-old son died, along with a 67-year-old grandmother and her 8-year-old grandson. Two 13-year-old girls were killed, along with a 25-year-old man visiting from Romania and four women ages 20 to 56.
Most of the injured were taken to nearby Hadassah Ein Kerem, where the number of patients admitted because of the violence rose to more than 2,000 since the uprising began 26 months ago. A teen-ager injured in a suicide bombing last December remains at the hospital with a nail lodged in his brain.
Israeli Prime Minister Ariel Sharon convened an emergency session of his Security Cabinet yesterday, and aides said he ordered a "wide and extensive" military response, though no details were immediately divulged.
Israeli troops arrested the bomber's father and brother in a village south of Hebron yesterday afternoon. Last night, soldiers were in el-Khader, making arrests and occupying 30 homes.
Early today, the Israeli army reoccupied Bethlehem, from which it had withdrawn in August when the Palestinians promised to restore order. Expecting an invasion, Palestinian police in Bethlehem had abandoned their posts. No casualties were immediately reported.
Several of Sharon's Cabinet ministers advocated sending the army into Gaza City and arresting or killing top Hamas political figures, such as the group's spiritual leader, Sheik Ahmed Yassin, or its founder, Abdel Aziz Rantisi.
Israeli forces went deep into Gaza City earlier this week and raided the offices of Palestinian Preventive Security. Army officials said troops seized rockets, mortars, guns and detailed maps of Jewish settlements - evidence, they said, that proves direct complicity by the Palestinian Authority in militia activity.
Yesterday's bus bombing was the latest in a string of recent attacks. Five Israelis were shot to death last week at a communal farm in the country's north, and a dozen soldiers, police and security guards were killed in a shootout last Friday in the West Bank city of Hebron.
The attacks come in the midst of a national election campaign in which security is the central issue. Candidates from the center-left Labor Party and the rightist Likud Party are offering voters a distinct choice between conciliation or the use of heavy force to end the Palestinian conflict.
Yesterday's suicide bombing brought the usual stern demands from Israel's political right to expel Palestinian leader Yasser Arafat and end any prospect of a Palestinian state - actions that Sharon said he would not take, even at the risk of alienating some in his own party, because they run counter to U.S. foreign policy.
The Palestinian Authority, which has failed to persuade militant groups to cease their attacks, condemned the bombing in unusually harsh language, calling the targeting of civilians "a morally and politically reprehensible act [that] undermines our people on the international scene."
Palestinian officials say further attacks would only help Israel's right wing and want them stopped at least until after the election Jan. 28. But Palestinian militant groups such as Hamas oppose negotiations and contend the attacks will hasten an Israeli withdrawal from occupied territories.
"What is coming is bigger and, God willing, greater," a statement from Hamas said.
On Wednesday, U.S. Ambassador Daniel C. Kurtzer told a group of visiting New York officials that Arafat has failed to initiate reforms that could bring a halt to such attacks.
"We're not optimistic," Kurtzer said.
Yesterday's bombing was the first attack in Jerusalem in three months, breaking what some Israeli officials nervously called a "scary quiet" that gave residents a false sense of security.
That period of relative calm was shattered by the wail of ambulance sirens, which drowned out the honking horns that typically mark the morning rush hour. Television screens filled with images of yet another bus blown apart and a street littered with victims, blood-spattered purses, homework papers and uneaten sandwiches.
Again there were cries for revenge and expressions of anguish by those who were supposed to be on the bus but weren't. Police with machine guns set up makeshift roadblocks throughout the city. Usually busy streets emptied as a new sense of gloom set in.
"We are sick and tired of this life," said Tamar Chana, whose son Jacob was on the bus and injured slightly.
The blast caved in the front of the bus, blew out the windows and peeled away the roof.
Police said the bomber apparently waited for the bus to fill, then blew himself up two stops after he boarded. The explosives went off near the middle of the bus just as it was approaching the final stop in the neighborhood, when it is usually too full to find a seat.
Yana Ha'amov, 19, usually takes the No. 20 bus to downtown, where she gets a connection to her army base. Yesterday morning, though, she felt sick and stayed home. She heard the blast from her apartment and raced to the stop.
"I could have just died," she said, shaking.
Maor Kimche, the 14-year-old recovering at Hadassah, said he never saw the bomber but must have brushed by him as he made his way to the back. After the explosion, Maor said, he crawled through a window and was helped by a taxi driver, who drove him to the hospital. He called his mother on a borrowed cellular phone.
"Mom, there was an attack on the bus," he told Elana Kimche, 41. "Don't worry. I was injured lightly on my leg."
Maor's father said his family has no choice but to use buses. Maor goes to school in downtown Jerusalem, on Street of the Prophets, another frequent site of attacks, and was 100 yards from a bombing on King George Street this year.
"Why wouldn't I let him ride the bus?" said Doran Kimche, 44. "Because it's dangerous? If I don't let him ride, then the terrorists will have gotten what they want."
Maor had a more practical reason for riding.
"How else would I get to school?"