Massive Arson Attack: Rail network hit before Paris Olympics opening.
Paris Station Delays: Major delays affect 800,000 people.
SCNF Statement: Attacks aimed to damage installations.
Fire Timing: Fires began at 4 a.m.
Authorities' Response: Not labeled terror attack; severe disruptions.
Transport Minister's Condemnation: Minister condemns attacks; warns of travel disruption.
Targeted High-Speed Lines: High-speed rail lines were main targets.
Coordinated Acts: Fires on multiple lines; one stopped.
Repair Timeframe: Repairs will take all weekend.
Eurostar Advisory: Passengers advised to postpone trips.
Olympics Impact: Attacks hours before Olympics opening.
Developing Story: Further updates expected.