Boston school bus drivers went on strike Tuesday morning — with no advance warning to families — leaving thousands of children stranded at home or at bus stops as the city grappled with its first such strike in more than two decades.
Drivers showed up before dawn, but most refused to board their buses to protest myriad grievances, from payroll problems to a new Web page that allows parents to track their children’s buses. Bus yard managers eventually ordered them off the four lots and locked the gates, as union members shouted back and forth, with police cruisers parked nearby.
It remained unclear whether the drivers, who work for a private company contracted by the city, would return to their jobs Wednesday morning. Mayor Thomas M. Menino urged families to make contingency plans after the company unsuccessfully sought a federal court injunction to end the strike. He also said schools would open an hour early to accommodate parents dropping off children while trying to get to work.
Menino portrayed the strike as illegal. The union contract forbids strikes, and participants could face termination. The union’s parent organization, the United Steelworkers, and the local’s president, Dumond Louis, urged drivers to return to work, exposing a potential division within union ranks.
“I am extremely angry,” Menino said at an evening press conference at City Hall. “These are selfish people who only want to cause disruption in our city. . . . This union cannot stop our schools from educating young people. The only thing in jeopardy here is their own livelihood.”
In ways large and small, the strike disrupted the fabric of life in the city. Parents scrambled to find alternative transportation; some simply walked their children more than a mile to class. Dozens of police officers getting off their midnight shifts pitched in, as well, driving students to their schools.
Absenteeism skyrocketed across the city, as 9,600 students missed school, nearly three times the normal number. Schools were forced to reschedule tests and cancel afterschool athletic events and other extracurricular activities.
Councilor at Large John R. Connolly and state Representative Martin J. Walsh, aiming to replace a retiring Menino, both assailed the strikers.
Outside the Readville bus yard in Hyde Park Tuesday night, bus drivers cheered after they learned that a judge had denied the injunction against the strike.
Steve Kirschbaum, chairman of the bus union’s grievance committee, said members are simply asking that its contract be honored by Veolia Corp., which oversees the bus fleet for the city. He characterized the situation as an “illegal lockout,” saying Veolia ordered drivers off its property under the threat of arrest.
“If they really care about the students of Boston, come and show respect to those of us who drive the city’s most precious cargo,” Kirschbaum said. “We stand prepared to negotiate any time, anyplace, anywhere.”
The strike rippled far beyond the city’s system, affecting even charter, parochial, and many private schools that rely on the yellow buses. About 30,000 students take the buses each day, but only about three dozen of the 732 buses made it out of the city’s bus yards.
“The bus drivers did an injustice to the students,” said Erin McGrath of Dorchester, who had to take the day off from work to transport her son to and from the Condon School in South Boston. “They have a contract — live by it. You don’t do this to children.”
The strike is the latest debacle for the city’s school bus system, which was marred with chronically late buses for two school years, reaching a crisis level in fall 2011, when 37 percent of the buses ran up to an hour late at the start of the school year.
Since then, the School Department has worked painstakingly to get buses arriving on time — with more than 90 percent typically now arriving before the bell — and it hired Veolia, which took over in July.
But acrimony has been growing between the union and Veolia. In August, the union filed a complaint with the National Labor Relations Board, outlining their complaints, which included concerns over changes to the health care plan and new procedures instituted by Veolia.
Many union members became further enraged Thursday after a popular manager at the Readville yard lost her job, and members prepared to rally Friday to protest. But they later learned she would keep her job, and the rally became more of a meeting. The issue flared again Tuesday morning after many drivers found out she would not be coming back.
School Department spokesman Brian Ballou said officials had heard rumblings about the strike Monday and had placed monitors at bus yards Tuesday morning. They learned of the strike shortly after 5 a.m.
But some parents questioned why neither the School Department nor the union alerted parents ahead of time.
“In the past, the union has been proactive in letting parents know there was an issue,” said Samuel Hurtado, who has two children in the Boston schools and works with South Boston en Accion, a Latino advocacy organization. “Ultimately, it’s affecting the education of our children.”
The bus drivers’ union frequently threatens to strike, but common ground almost always is found. The last time the bus drivers are believed to have gone on strike was in fall 1991, when negotiations over a new contract soured. The strike lasted for nearly five weeks, forcing families to come up with their own transportation.
All day Tuesday, Menino repeatedly urged drivers back to work, to no avail. The two candidates seeking to replace him joined in the call.
“It is shameful for the school bus drivers union to use our children as pawns in a political game,” Connolly said. “This is about safety first and foremost, and it is totally unacceptable that our children were put at risk this morning, not to mention the impact on thousands of parents who will miss work. Missing even one day of school is a real problem for our children who face a daunting achievement gap.”
Walsh said: “Kids and parents must come first. This is wrong. The bus drivers have put our children in harm’s way. This is an illegal action, causing a huge disruption, and I call on the bus drivers to return to work immediately. This is a violation of the contract and cannot be tolerated.”
As outrage swept across the city, confusion emerged over whether the union’s leadership or a faction of the group was orchestrating the strike. The union president was booed when he ordered drivers at the Readville yard to go back to work at 8:30 a.m., but he was more tempered in his comments when he spoke later. He was flanked by two representatives from the national union who faced jeers when they called the strike illegal.
During the request for the emergency court injunction, an attorney for the union, Patrick Bryant, blamed the strike on a group of rogue employees led by Kirschbaum.
“The union cannot be responsible for this predicament,” said Bryant, adding that at this time “the idea that we should go through this kabuki theater is unnecessary.”
In refusing to grant the injunction, US District Court Judge George A. O’Toole Jr. ultimately agreed with Bryant that the union contract has a provision that requires union leadership to order members back to work. But he left open the possibility of revisiting the issue.
Paul J. Hodnett, an attorney for Veolia, said he was disappointed with the ruling, saying the massive walkout was clearly union-sanctioned.
Meghan Irons, David Abel, Martin Finucane, Milton J. Valencia, Maria Cramer, Wesley Lowery and Matt Carroll of the Globe staff and correspondents Jasper Craven and Dan Adams contributed to this report.