Services by the Swiss Federal Railways were returning to normal on Thursday after a nationwide power network breakdown left 100,000 passengers stranded.
The Railways said a short circuit on one of its power lines prompted a chain reaction that led to the outage all over the country.
The first trains began running again at around 8:15pm on Wednesday evening, more than two hours after the entire system collapsed - the first time in its history that the Federal Railways has suffered such a breakdown.
International inter-city trains passing through Switzerland were also affected, as well as train lines of some smaller Swiss railway companies.
Trains were generally running to schedule on Thursday morning, but the railways said that some services had been cancelled and trains were not all in their usual configuration.
Officials said the short circuit that took place north of the Alps meant that current generated by the railways' power stations near the Gotthard Pass was flowing entirely onto the southern section of the network.
This led to the grid being overloaded and power resources needed by the railways were shut down.
Shortly after the system shutdown, emergency crews were summoned to remove trains stuck in tunnels, and passengers trapped in stranded trains were evacuated after train air-conditioning systems stopped functioning.
Hansjörg Hess, head of the Federal Railways' infrastructure department, told swissinfo it was too early to provide an estimate of how much the breakdown would cost the Railways.
"It might take a week to work out what the cost of this incident is likely to be," he said.
swissinfo with agencies
The Federal Railways transports about 700,000 passengers a day.
The Railways increased the number of regularly scheduled trains by 12% at the end of 2004.
The country's railway network has 5,100 kilometres of track, normal and narrow gauge.
In compliance with the JTI standards