The deadly train crash in southern Spain has darkened one of the country’s proudest modern achievements.

The collision Sunday killed at least 40 people and injured dozens more, officials said Monday night.

Here is a snapshot of the rail system that became a crown jewel of contemporary Spain, by the numbers.

Spain launched its first high-speed AVE line, AVE means "bird” in Spanish, marking a turning point in national infrastructure.

Before and after that milestone, successive governments poured tax revenue and European Union development funds into the network, allowing Spain’s high-speed rail system to rapidly catch up with, and eventually surpass, early pioneers such as Japan and France.

The first high-speed train to cross Spain debuted two months before the opening of the 1992 Summer Olympics in Barcelona.

Both marked high points in Spain’s recent history after it emerged from the economic doldrums and cultural and political isolation of the 20th-century dictatorship of Gen. Francisco Franco.

The number of kilometers, about 2,400 miles, of high-speed rail Spain has laid over the past three-plus decades for its 49 million residents.

Only China, with about 45,000 kilometers (28,000 miles) for its 1.4 billion people, has more high-speed track, according to the International Union of Railways.

Spain’s commitment to high-speed rail, which the rail union defines as lines designed for trains traveling at least 250 kph (155 mph), has helped the country shed a reputation for lagging behind other leading industrial economies.

Spain’s train builders have capitalized on that domestic expansion. A Spanish consortium built Saudi Arabia’s high-speed rail line connecting the holy cities of Mecca and Medina, which opened service in 2018.

The approximate number of hours a train trip took between Madrid and Barcelona before and after the adoption of high-speed rail in 2008.

On older conventional trains, the 600-kilometer (385-mile) journey between Spain’s two largest cities took about seven hours, prompting many business travelers to fly.

That trip can now be completed in about 2.5 hours. Spain announced plans in November to modernize the Madrid-Barcelona line to allow trains to reach speeds of up to 350 kph (218 mph), matching the fastest Chinese trains and cutting travel time to under two hours.

The AVE has helped unite a country whose main population centers, outside Madrid, lie along the coasts, separated by some of Europe’s most sparsely populated areas.

Every region and provincial capital has pushed for its own high-speed line. Critics say governments may have spent too much on marginal routes at the expense of local commuter rail, which suffers far more frequent delays than high-speed service.

Lacking an AVE stop has become synonymous with economic decline for some provincial cities.

The shift from air travel to rail is also a central pillar of Spain’s green energy and electrification strategy to combat climate change.

The number of deadly accidents involving high-speed trains in Spain’s history. One official described Sunday’s collision as turning a train into a "mass of twisted metal.”

Officials say they are still trying to determine what went wrong Sunday night, when one high-speed train derailed and collided with another traveling in the opposite direction.

Alvaro Fernandez, president of the state-run rail operator Renfe, told Spanish public broadcaster RNE that both trains were traveling well below the speed limit and that "human error could be ruled out.”

One train was operated by Renfe and the other by a private company.

Spain’s deadliest train accident this century occurred in 2013, when 80 people were killed after a train derailed in the country’s northwest. Investigators concluded the train was traveling at 179 kph (111 mph) on a stretch with an 80 kph (50 mph) speed limit. That section of track was not high-speed rail.

The number of operators running high-speed trains in Spain.

Spain opened its rail network to private competition in 2022.

The first private operator was Iryo, which is Italian-owned, followed by the French company Ouigo.

It was an Iryo train that first derailed Sunday, knocking a Renfe train off the tracks. Iryo said it is cooperating fully with authorities to determine the cause of the crash.