Congressional Limited derailed there, killing 79 and injuring 117 of the 541 on board. Infrastructure The NEC is a cooperative venture between Amtrak and various state agencies. Amtrak owns the track between Washington and New Rochelle, New York, a northern suburb of New York City. The segment from New Rochelle to New Haven is owned by the states of New York and Connecticut; Metro-North Railroad commuter trains operate there. Amtrak owns the tracks north of New Haven to the border between Rhode Island and Massachusetts. The final segment from the border north to Boston is owned by the Commonwealth of Massachusetts. Electrification At just over , the Northeast Corridor is the longest electrified rail corridor in the United States. Most electrified railways in the country are for rapid transit or commuter rail use; the Keystone Corridor is the only other electrified intercity mainline. Currently, the corridor uses three catenary systems. From Washington, D.C., to Sunnyside Yard (just east of New York Penn Station), Amtrak's 25 Hz traction power system (originally built by the Pennsylvania Railroad) supplies 12 kV at 25 Hz. From Sunnyside to Mill River (just east of New Haven station), the former New Haven Railroad's system, since modified by Metro-North, supplies 12.5 kV at 60 Hz. From Mill River to Boston, the much newer 60 Hz traction power system supplies 25 kV at 60 Hz. All of Amtrak's electric locomotives can switch between these systems. In addition to catenary, the East River Tunnels have 750 V DC third rail for Long Island Rail Road trains, and the North River Tunnels have third rail for emergency use only. In 2006, several high-profile electric-power failures delayed Amtrak and commuter trains on the Northeast Corridor up to five hours. Railroad officials blamed Amtrak's funding woes for the deterioration of the track and power supply system, which in places is almost a hundred years old. These problems have decreased in recent years after tracks and power systems were repaired and improved. In September 2013, one of two feeder lines supplying power to the New Haven Line failed, while the other feeder was disabled for service. The lack of electrical power disrupted trains on Amtrak and Metro-North Railroad, which share the segment in New York State. Stations There are 109 active stations on the Northeast Corridor; 30 are used by Amtrak. All but three (, , and ) see commuter service. Amtrak owns