— In the pious Har Nof neighborhood in the hills of West Jerusalem, early-morning prayers at a landmark synagogue are an integral part of the rhythm of daily religious life.
Those who chose that time and place to strike seemed to know that.
Two attackers brandishing weapons including a handgun and a meat cleaver burst into the synagogue early Tuesday, killing four worshipers — three of them with American citizenship, including a prominent rabbi, and the fourth a British national.
The assailants, shot dead by police units that converged on the scene within minutes, were identified as Palestinian cousins from predominantly Arab East Jerusalem, a site of violence in recent months.
A police officer wounded in the confrontation died later Tuesday.
The White House identified the slain Americans as Aryeh Kupinsky, Cary William Levine and Moshe Twersky — the last a member of a noted Hasidic dynasty. Israeli news reports identified all four men as rabbis.
Members of Baltimore's Jewish community, many of whom have lived in or travel regularly to Israel, planned to gather at the Shomrei Emunah synagogue in Pikesville Tuesday night.
Rabbi Avraham Rosenblum said he and many others in Baltimore's Orthodox community have close ties to Har Nof. He lived two blocks away from the synagogue 25 years ago, and he visits regularly.
"In the American Orthodox world, everybody knows everybody," Rosenblum said. "We feel it very acutely."
Rosenblum said Twersky taught "a significant number" of the hundreds who that packed Shomrei Emumah.
Rabbi Ariel Sadwin, who helped organize Tuesday's service, called the killings — and, in particular, the images of rabbis slain in their religious vestments — vestiges "unspeakable."
"I've never seen that before," he said.
Because the attack happened at prayer time and the victims were immigrants, Rabbi Shmuel Silber said, it has hit the community particularly hard.
"We're shocked and heartbroken," said Silber, of the Suburban Orthodox Congregation in Pikesville. "It's a terrible and catastrophic event."
Twersky came from one of the most revered families in Boston's Orthodox community. His late grandfather, Rabbi Joseph Soloveitchik, founded the Maimonides School in suburban Brookline, considered the first Jewish day school in New England and a cornerstone of the Modern Orthodox movement, which aims to bridge religion and modern life.
Twersky's father, Rabbi Isadore Twersky, was a longtime professor at Harvard University and director of its Center for Jewish Studies.
Moshe Twersky graduated from Maimonides in 1973 and moved to Israel, where he became dean of Jerusalem's Toras Moshe yeshiva, or religious school.
Chana Siff, of the Baltimore Israel Coalition, said many families in the Baltimore area have ties to Twersky's school.
Siff once lived in the neighborhood where the attacks took place.
"It's much quieter than most neighborhoods in Baltimore City," she said. "The children run the streets like there's no care in the world."
Siff's group had planned an event this Sunday to consider what it sees as rising anti-Israel feeling when news of the attack came Tuesday.
Prime Minister Benjamin Netanyahu described the attackers as "animals" and vowed a harsh response to the killings. He blamed Palestinian incitement.
The assault horrified Israelis, drew international condemnation and threatened to further inflame Jewish-Muslim tensions, which were already running high over a contested Jerusalem holy site.
At least six Israelis remained hospitalized in the wake of the attack, the deadliest in Jerusalem since 2008.
President Barack Obama condemned the assault, saying "it is all the more important for Israeli and Palestinian leaders and ordinary citizens to work cooperatively together to lower tensions, reject violence and seek a path forward towards peace."
Tuesday's attack appeared to fit a pattern of recent "lone wolf" attacks by Palestinians embittered in part by the dispute over the holy sites, but it was somewhat more sophisticated and carried out by two people. Israeli officials have not suggested that the assaults are orchestrated by any particular group but have accused Palestinian leaders and media of encouraging the anger.
The pair who carried out Tuesday's attack, identified by authorities as Udai Abu Jamal and Ghassan Abu Jamal, "have no previous security records and did not operate within the framework of any organization," the head of the domestic intelligence agency Shin Bet, Yoram Cohen, told members of a Knesset committee after the incident, the Haaretz newspaper reported.
Witnesses described panic and pandemonium at the synagogue. The dead and wounded crumpled to the floor, still clutching sacred texts. A 12-year-old boy whose father was seriously wounded crawled on the bloodied floor to escape and summon help.
For many Israelis, the specter of a calculated strike against Jews at prayer, in ritual garments, carried chilling overtones of historic persecution.
"Jewish worshipers lay dead in pools of blood, still wrapped in prayer shawls and phylacteries, with holy books strewn on the floor," Yehuda Meshi-Zahav, who heads Zaka, an emergency response group led by Orthodox Jews, told Israel Radio. "Such sights I have never seen — they recall dark days."
Eyewitness Yaacov Amos said the attack came in the midst of the Shemoneh Esrei, the prayer at the heart of the Jewish liturgy.
"I suddenly heard shots," said Amos, 45. He said he took cover behind a lectern.
"The shock was not to be believed — in the middle of this prayer, of all prayers, here in our synagogue, before my very eyes, at a range of zero."
U.S. Secretary of State John F. Kerry called Netanyahu and expressed condolences for the attack. "This simply has no place in human behavior," Kerry told reporters in London.
Netanyahu, who summoned top security officials to an emergency meeting, declared that the "despicable murderers" would not go unpunished. Within hours, a massive police contingent raided the family homes of the two assailants and arrested more than a dozen family members, according to Palestinian accounts.
The Israeli leader said the attackers' homes would be demolished — a practice largely abandoned in recent years — and "inciters" held to account.
A government statement said unspecified "additional decisions … have been made in order to strengthen security throughout the country." Israel had already redeployed hundreds of troops to the West Bank after a pair of lethal stabbings last week.
In the wake of Tuesday's attack, Israeli forces in East Jerusalem and several parts of the West Bank battled stone-throwing protesters, clashes that continued as night fell. A light-rail train passing through an Arab neighborhood of Jerusalem was pelted with rocks, forcing it out of service.
At Kerry's prompting, Palestinian Authority President Mahmoud Abbas issued a denunciation of the attack, but coupled it with a call for a halt to Israeli "intrusions" on a site in the walled Old City revered by Jews as the Temple Mount and Muslims as the Noble Sanctuary.
The militant Hamas movement praised the attack but did not claim any involvement. Celebratory gunfire rang out in the Hamas-dominated Gaza Strip and at several locations in the West Bank, and the group's spokesman Sam Abu Zuhri called the assault a response to the "continuing crimes of the occupation."
Israeli police spokesman Micky Rosenfeld said allegations by some neighborhood residents that the attackers had worked in a shop near the synagogue had not been confirmed, but authorities were investigating the assailants' ties to the Har Nof area. Palestinians with Jerusalem IDs often work in the city's western neighborhoods.
The brutal nature of the attack, the shock of a strike on a house of prayer, and the fact that the episode took place in a part of Jerusalem considered far removed from recent clashes, boded ill for any calming of the violence that that has roiled the city in recent months.
Four people on the Israeli side of the city have been killed in the past month in vehicular attacks by Palestinians, and in a spreading of "lone wolf" attacks outside the city, a soldier was stabbed to death in Tel Aviv last week and a Jewish woman killed outside a West Bank settlement bloc.
Netanyahu blamed Palestinian leaders this week for inciting such attacks, telling Israelis in a nationally televised appearance that "Hamas, the Palestinian Authority and others spread libel and lies against the people of Israel every day."
Much of the current burst of ill feeling is centered on the Temple Mount or Noble Sanctuary, a hilltop in the Old City revered by both Jews and Muslims. Jews are allowed to visit the site but not to pray there, and activists — some from within Netanyahu's government – have been calling for a change to that longstanding "status quo," infuriating Muslims across the Islamic world.
Kerry visited Jordan, the formal custodian of the site, last week to try to ease frictions, winning pledges from both Netanyahu and Abbas in separate meetings for calming measures. But calls for moderation are likely to be lost in the outcry over the attack, and any retaliatory strikes that arise from it.
"We're at war," Israeli lawmaker Aryeh Deri, who comes from the neighborhood where the attack took place, told Israel Radio. Neighbors and relatives of the attackers described them as heroes of the Palestinian cause.
Palestinian media depicted the synagogue attack itself as retaliation, coming after an Arab bus driver was found hanged Monday at a bus depot in West Jerusalem. A forensic report ruled that there was no sign of foul play and that the death was a suicide, but Palestinian media reports sharply contested the impartiality of the examiners.
Tuesday's assault was the most lethal in Jerusalem in six years, since a yeshiva on the city's outskirts was attacked by a gunman, killing eight of the religious students. An off-duty army officer killed that attacker.
King is a Los Angeles Times staff writer and Sobelman is a special correspondent. Special correspondents Maher Abukhater in Ramallah, West Bank, and Tami Zer in Jerusalem. Baltimore Sun reporters Ian Duncan and Colin Campbell, and Reuters contributed to this article.