NEW YORK — It had long been considered a dangerous crossing, with more than 200 commuter trains barreling by every day, traveling up to 80 mph — even as streams of cars waited to drive over the tracks.

It was so troubling that it was one of seven hazardous crossings along a 20-mile stretch of Long Island Rail Road track that were scheduled to be eliminated.

The construction work at the crossing in Nassau County was set to begin next year; plans called for a bridge for trains and an underpass for vehicles. But that was not soon enough to avoid a rush-hour tragedy Tuesday.

Two Long Island Rail Road trains traveling in opposite directions slammed into a vehicle that had apparently driven around the crossing gates on School Street in Westbury. Three people, all of them inside the vehicle, were killed.

Passengers on the two trains scrambled to safety, fleeing flames that they worried would engulf one train and dodging debris that smashed through the front of the other. For a brief, terrifying moment, rails twisted, metal crunched, windows shattered, and each train wobbled. Panicked passengers dreaded that the cars would tip over before they could get out.

Of the hundreds of people on the trains, seven were taken to Nassau University Medical Center. Three were admitted, doctors at the hospital said.

On Wednesday, officials were still determining why the vehicle had worked its way around crossing gates that witnesses said were down. Red warning lights had also been blinking. Officials said that at least one witness had indicated that the vehicle had been in an accident and was apparently fleeing the scene of that incident when it made its way onto the tracks.

An eastbound train that had just left the nearby station in Westbury struck the vehicle first, spinning it around. Then, a westbound train going much faster bore down on the vehicle and crashed into it.

Sandwiched between the two trains, the vehicle burst into flames and was all but destroyed. “All that we have left of it is the engine itself,” the Nassau County police commissioner, Patrick Ryder, said Wednesday.

The westbound train continued on its doomed path in a scene that some witnesses said resembled a disaster movie, with the train hurtling toward the Westbury station, then crashing into its platform. The force of the impact drove chunks of concrete and pieces of metal into the front of the train amid a shower of sparks.

The engineer turned and grabbed a passenger in the first car, shoving the person away from the debris, Ryder said, adding that the engineer would have been killed had he not abandoned his place at the controls.

A floor manager at the Fine Fare grocery store on Old Country Road, about a half-mile from the crash site, said Wednesday afternoon that the occupants of the car worked at the store, and had for about seven years.

A memorial table with a cardboard donation box and photographs of the men was placed at the front end of the store, in front of the cash registers. A printed message on the box read, “We thank you for your support for their families, in loving memory of our dear friends and co-workers,” with the message repeated in Spanish.

“Good people, that’s all I can say,” the manager, Giovanny Taveres, said after he placed a black ribbon on a memorial table. “Good people, hardworking people.”

Taveres said all three of the men had worked Tuesday — two worked in the meat department, and one ran the store’s dairy department. They left work saying they were headed to a barbershop to get haircuts, Taveres said.

The vehicle involved in the crash had been at a nearby shopping strip before it headed toward the crossing, according to employees and customers of the barber shop, Los Primos.

One barber at Los Primos said the men had come in at about 5 p.m. Tuesday for haircuts, then went to a bar and restaurant next door. They left after a couple of hours, the barber said.

As they left, he said, they had a minor accident — he described it as a fender bender — with another car. The other driver said she would call police, the barber said.

She returned to her car to make the call, he said. The men pulled away and headed toward the railroad tracks.

On Wednesday, the railroad canceled 12 trains on its busy Main Line. During the morning rush, Manhattan-bound trains squeezed by the wreckage on one track because the accident had made the second track impassable. The westbound train remained where it had come to a stop, the twisted rail beneath it complicating efforts to clear the corridor and replace the ruined track. A crane arrived, apparently to free the cars.

Officials from the Metropolitan Transportation Authority, which oversees the Long Island Rail Road, expressed sorrow over the deaths. Philip Eng, the president of the railroad, said drivers should not try to sidestep crossing gates.

“Why folks try to risk their lives and other people’s lives, perhaps to save a few minutes, is one I can’t answer,” he said in response to a reporter’s question at a news conference.

Gov. Andrew Cuomo and the Nassau County executive, Laura Curran, called for the National Transportation Safety Board to investigate the crash. But a spokesman for the board said it had no immediate plans to do so because it did not see any broader national issues or safety problems.

Street-level crossings have long been a hazard in the New York City region, which is crisscrossed by three major commuter railroads with hundreds of spots where streets run across tracks. In 2015, a crowded Metro-North Railroad train slammed into an SUV on the tracks at a crossing in Westchester County. The fiery crash killed seven people — the driver of the SUV and six people on the train.

As for the Long Island Rail Road, Cuomo last year announced a plan to replace the seven crossings, and add a third track for about 10 miles through Queens and Nassau County.

He said at the time that people had talked about upgrading the Main Line and improving safety “since the 1940s.”

There were six fatal crashes on the Main Line between 2007 and 2017, according to the transit agency.

One of them, at the School Street crossing in 2009, involved a 56-year-old man who apparently threw himself in front of a train, Federal Railroad Administration records showed. Peter I. Cavallaro, the mayor of Westbury, said the crossing had “always been a concern for both pedestrians and for cars” in the village.

Too often, the crossings invite a dangerous combination of cars, trains and human nature: impatient drivers who drive around the crossing gates, thinking they can beat a train. Drivers also sometimes disregard the gates when they have been down for a while, assuming they are stuck.

By the time drivers reach the gates, they have ignored other warnings. Painted on the pavement are railroad crossing signs and thick, white lines that are supposed to stop motorists tempted to skirt the gates.

Mortimer L. Downey, who was a deputy transportation secretary during the Clinton administration, said accidents at crossings were a major problem for railroads.

“In a collision between you and the locomotive,” he said, “the locomotive is always going to win.”

In 1982, a van in Mineola, about 4 miles from the site of Tuesday’s crash, drove around crossing gates and was struck by a five-car train. Nine teenagers were killed in the late-night crash. The state decided to build a railroad bridge over the crossing, but the project took 16 years and $85 million to complete.

The School Street crossing was set to be eliminated as part of the $2.5 billion upgrade. The proposal also called for widening or raising bridges along the Main Line to reduce the chances of hitting abutments.

The railroad also planned to install an automatic braking system designed to prevent a crash if a train operator does not apply the brakes fast enough.

The Long Island Rail Road has 296 street-level crossings, and agency officials said the number of accidents at the crossings had declined drastically in recent years.

In 2017, there were 17. In 2018, there were seven, all before the Long Island Rail Road became the first in the country to put attention-getting flexible delineators — rubber posts attached to the surface of the street that bend if someone drives over them — on all of its street-level crossings. The railroad also said it had worked with online app Waze to ensure that GPS devices alerted drivers when they were approaching such crossings.

The railroad said there have been no incidents involving motorists turning onto the tracks and going through street-level crossings since it installed the delineators. It put new reflective paint on the pavement leading to the crossings at the same time.

The crossing where Tuesday’s crash happened is in an industrial triangle, with a waste-transfer station on one side of the road. A factory for a metal-fabricating company was on the other side until recently, when the building and its lot were taken for the planned improvement project.

Just before the accident, passengers on the eastbound train realized that something was wrong. “It felt like there was metal banging on the bottom of the train,” said Jose Gomez, a passenger in the second-to-last car.

The train stopped, the power went out, and the westbound train passed by making a similar noise, he said.

A few minutes later, passengers on the westbound train saw flames streaking along the metal skin of Gomez’s train.

“It felt like you were going through a furnace momentarily,” said Nirmal Mitra, a copy editor at Newsday who was on his way home on the westbound train. He said the train rattled, and there was a more powerful thud.

“I thought we were going to get derailed,” he said.

This article originally appeared in The New York Times.