Thousands of parents scrambled for alternate means to get their children to school as the school bus drivers union began the strike it had vowed to hold failing a resolution by Wednesday morning on a dispute over new contracts.

Some 152,000 children — or about 14 percent of the student population — take the bus. About 54,000 of them have disabilities and face extra hardships in trying to find ways to school.

City officials Tuesday blasted the planned strike by Local 1181 of the Amalgamated Transit Union for leaving tens of thousands of children in the lurch as union members said they would do what they had to do to protect their jobs. Bus drivers were planning to report to picket lines Wednesday morning as the city braced for its first school bus strike in more than three decades.

Bus Strike Survival Guide

The union and the city have been battling over how new contracts are being drawn up for a set of bus routes. The city wants to cut transportation costs and has put about 1,100 bus contracts with private bus companies up for bid. The union is decrying the lack of Employee Protection Provisions, saying without the so-called EPPs, current drivers could suddenly lose their jobs once their contracts are up in June.

Less than an hour after the strike officially began, Schools Chancellor Dennis Walcott reiterated to NBC 4 New York what Mayor Bloomberg had said Monday — that the union wants job protections the city cannot legally provide under competitive bidding regulations. Union President Michael Cordiello has said that claim is inaccurate.

Walcott said he understood the additional stress the strike would place on families, but said the city’s hands were tied on the matter.

“We’re putting a bid out to make sure we get the best service for our students. We have a responsibility to the taxpayers to put in a request for bids,” Walcott told NBC 4 New York. “We will never compromise the safety of our students, plain and simple. We know it’s going to be tough for our parents and children.”

The city began taking measures this week to alleviate additional hardships imposed by the strike, including by passing out free MetroCards for children to take mass transit to get to school. Walcott said the MetroCards for children would be active Wednesday, while parents or guardians of students would have access to free MetroCards Thursday. In the meantime, they would be reimbursed for transportation.

The free city subway or bus passes were not much of a solution for many families.

Grandmother Janet Balmes said it’s ridiculous to expect her 5-year-old grandson would take a city bus to school.

READ MORE: NBC NEW YORK