In the wake of the fire beneath the elevated Metro-North Railroad tracks in East Harlem, there are far more questions than answers.

Right now, commuters are worrying about long delays, and fans of the Urban Garden Center where the fire broke out worry about its future. But the four-alarm inferno, and the structural damage it caused to the train tracks’ viaduct, raises more serious concerns about the safety of the city’s many elevated commuter and subway tracks and trains.

Tuesday’s fire broke out in the garden center at 118th Street and Park Avenue, directly under the viaduct that carriesthe Hudson, Harlem and New Haven lines. Steel bent, bolts popped and the trestle and columns were damaged to the point that the MTA said it probably cannot restore full service until Friday.

The fire came two years after a gas explosion in that area killed eight people, destroyed two buildings and damaged the garden center. Fire marshals said Tuesday’s fire was an accident caused by fuel spilled on a hot generator. It’s clear that we need to pay attention to the land under the elevated trains and subway rails that carry thousands of commuters throughout the city.

The garden center is part of La Marqueta, a historic outdoor market with multiple vendors managed by the city’s Economic Development Corp. The EDC’s revitalization of the space has been important to the community, but that effort need not jeopardize the safety of the tracks above.

The city has to determine whether regulations were followed, but also should address concerns over whether hazardous materials are stored below railroad tracks. Officials said permits had not been issued for propane tanks and gasoline kept at the fire site. The city and the MTA need to review how these vulnerable spaces are regulated, inspected, patrolled and secured.

At a time when we worry about terrorism, and about safety at airports, skyscrapers and train stations, we must not forget other potential targets in our transit infrastructure. Once there are answers about what happened Tuesday, let’s question how to safeguard our elevated rails, and the spaces below them.