Another migrant has died trying to board a British-bound freight shuttle near the entrance to the Channel Tunnel in France, officials have said.
The victim, believed to be Syrian, was reportedly electrocuted after attempting to clamber on to the shuttle in the latest fatal bid by migrants to reach Britain.
At least 10 have died trying to cross from Calais since the start of the migrant crisis, which has placed UK police and social services under huge strain.
In the latest incident, Channel Tunnel operator Eurotunnel said a shuttle was stopped shortly after leaving the platforms in Calais due to migrants on the tracks at around 10.20pm last night.
When the shuttle was searched, a number of migrants were found. One was unconscious and another was injured.
A Eurotunnel spokesman said: "The emergency services were called and immediately took them into their care. The authorities have subsequently confirmed the death of one of those taken into their charge.
"This sad incident shows once again that any attempt to travel illegally through the Channel Tunnel is fraught with danger."
Eurotunnel services from Calais were delayed by 30 minutes.
Tomorrow, British campaigners will be among those gathering in Calais. A one-minute silent lie-down will be held to mark the lost lives.
Campaigners also plan to march through "The Jungle" - where thousands are camped on the edge of the northern French port town - and on to Calais port.
An estimated 5,000 migrants displaced from countries including Syria, Libya and Eritrea are believed to be camped in and around Calais.
The surge in migrants attempting to cross the Channel prompted a string of measures to increase security at the terminal, including extra fencing and the deployment of more border force search and dog teams.
At its peak, the number of attempts to board lorries or trains was around 2,000 a night - but that has since fallen.
The crisis in Calais is part of a wider migrant surge in to Europe from countries in north Africa and the Middle East.
Croatia has closed all but one of its border crossings with Serbia after straining to cope with more than 13,000 migrants who have entered the country after Hungary closed its border.
Adrian Edwards, of UNHCR, said the crisis "is growing and being pushed from one country to another" as about 4,000 migrants pour in to Greece each day and head north.
The developments came as Germany's foreign minister said it might be necessary to force eastern European countries to accept quotas for migrants.
Earlier this month, Prime Minister David Cameron announced plans to take 20,000 people from camps in the Syrian region.
It came after pressure to admit more people from the war-ravaged country following the publication of photographs of three-year-old Aylan Kurdi, who drowned with his mother and brother trying to cross from Turkey to Greece by boat.
Britain is preparing to welcome the first group of Syrian refugees under the Government's expanded resettlement programme in the coming days.
Local authorities are starting to learn of the number of refugees they will be taking. In Hastings, East Sussex, the borough council said it will be taking around 100 refugees - 20 per year - over the next five years.