BRIDGEPORT, Conn. – Tens of thousands of commuters are bracing for a difficult trip around southwest Connecticut and to New York City beginning Monday as workers repair the Metro-North commuter rail line crippled by a derailment and crash.

Crews will spend days rebuilding 2,000 feet of track, overhead wires and signals after the train collision Friday evening that injured 72 people, Metro-North President Howard Permut said Sunday. Nine remained hospitalized.

“This amounts to the wholesale reconstruction of a two-track electrified railroad,” he said.

Several days of around-the-clock work will be required, including inspections and testing of the newly rebuilt system, Permut said. The damaged rail cars were removed from the tracks Sunday, the first step toward making the repairs.

Service disruptions on the New Haven line between South Norwalk and New Haven are expected to continue “well into the coming week,” Permut said.

Each day, about 30,000 Metro-North customers use the stations where service has been shut down, according to the Metropolitan Transportation Authority, which operates Metro-North.

Amtrak service between New York and New Haven also was suspended, and there was no estimate on service restoration. Limited service was available between New Haven and Boston.

About 700 people were on board the trains Friday evening when one heading east from New York City’s Grand Central Terminal to New Haven derailed just outside Bridgeport. It was hit by a train heading west from New Haven.

Investigators are looking at a broken section of rail to see if it is connected to the derailment and collision.