California train derails after collision with truck
 

A commuter train and a truck have collided, causing three carriages to derail northwest of Los Angeles.

http://www.bbc.co.uk/news/world-us-canada-31609770

The vehicle became engulfed in flames and at least 28 people have been injured, a fire department spokesman told the BBC.
Police in Oxnard, California, say the crash was first reported at 05:44 local time (13:44 GMT).
A helicopter from a local television station showed emergency responders treating multiple people.
A spokesman for the Ventura County Fire Department told the BBC that it is believed no one had died in the accident.

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Captain Mike Lindbery said the train was carrying 51 passengers, and 28 of those were transported to several local hospitals.
The driver of the truck that collided with the train fled the scene, and was "taken into custody south of the scene less than a mile," Capt Lindbery said.
The locomotive had a camera on the lead carriage, footage from which will be used in the investigation.
The National Transportation Safety Board (NTSB), the agency that leads transport investigations for the US government, said in a tweet, "NTSB launching team to rail accident in Oxnard, CA. More details to come."

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Aerial footage from the scene shows multiple emergency vehicles at the scene, with several fire fighters and paramedics moving people into ambulances.
One carriage can be seen overturned and laying partially in a nearby highway. Two others were overturned laying parallel to each other, and a fourth remains upright.
In a nearby intersection, the burnt-out shell of a truck can be seen with remnants of fire extinguishing foam.
The train was destined for Los Angeles, and crashed about 65 miles (100 kilometres) away from its destination.
A Metrolink train collided with a freight train in 2008 in another part of southern California, killing 25 people and injuring more.

Two conflicting safety aspects.

No different in method of operation to UK practice on the ECML, Anglia and WCML
If the stock is designed to operate that way no reason why it should not.

My query is why did the train split and at least 1 coach jacknifed round.
Normal design is to aim to maintain connection and remain in line through the couplings.

This is certainly true when all vehicles are of a similar mass. In most modern derailments the couplings/bars play a significant role in keeping the train together, and hopefully upright.

However in this consist the loco is at the rear. At the instant that the leading vehicle is in collision it is decelerating rapidly, whilst most of the mass of the train is still trying to push it forwards due to inertia.

Since modern carriages are designed to maintain their integrity and not concertina, I guess they have to dissipate the enormous energy of the impact by trying to move perpendicular to the direction of travel.

BW