The Roosevelt Island tram’s two gondolas are now safely tucked away on solid ground. That’s where they should stay. The money-losing tourist attraction, operated by a state authority, is obsolete and unsafe.

We’ve all heard the good news from Tuesday evening’s malfunction: The 68 people trapped in midair when the trams stalled were all eventually retrieved safely. Police and fire rescuers worked as a team. Private industry pitched in with a crane. While skill and hard work made these successes possible, luck was a big part of this story.

Here’s what didn’t happen the other night, but could have led to a very different outcome: Winds weren’t howling. Rain wasn’t pouring down. Both trams weren’t stuck above the East River. There were no medical emergencies. And perhaps most significantly, the trams weren’t crowded.

Each gondola has a 126-person capacity. The island-bound tram had 47 people aboard, while the Manhattan bound tram had just 21 passengers. The dearth of rush-hour passengers helps explain the safe rescue, and also helps explain why the tram operation is in the red.

Police commanders waited three hours to implement their rescue plan, holding out hope that – like every other time the increasingly unreliable tram system lost power over the last three decades – the power would come back on within a few hours. Once the rescue did begin, police needed two hours to set up the rescue bucket. And when the 12-person bucket finally began the slow trek toward the 47 island-bound people hovering over the East River, the process was maddeningly slow. Four round-trip rescue missions took about five hours.

What if the tram had been at capacity? Rescuing a full load would have required seven more trips, another seven hours, lasting until almost noon. Passengers whose supposedly four minute ride began just after 5 p.m. Tuesday would have been dangling above the East River for 18 hours. Realizing the bucket’s effectiveness was significantly diminished by its tediousness, city officials called in a crane to retrieve the 21 Manhattan bound passengers.

But what if that tram, suspended over First Avenue, had been just a few hundred yards away, over the East River? The crane wouldn’t have been an option. The rescue process, relying on that single bright orange bucket, would have dragged on into the next evening.

Tram fanatics could soon have new gondolas to gawk at. A more elaborate tram system is planned for linking Manhattan and Brooklyn to Governors Island. Presumably a modern tram will come with a modern power supply and a modern rescue plan.

Roosevelt Island’s tram is outdated and unreliable. It became redundant when the MTA opened a subway station on the island two decades ago. Those shiny red gondolas are long overdue for a museum. Or a trash heap. Anywhere but in the air.

Mr. Goldin’s column appears regularly.