LONDON (AP) – An independent review concluded Friday that Eurostar must better protect its electronic gear from melting snow and improve its communications system to avoid debacles like the one in December that stranded five trains in the tunnel between France and the UK for hours.

The review said filters apparently failed to prevent moisture from causing short circuits and needed to be improved.

“There is absolutely no doubt that these incidents were caused by a large quantity of fine snow entering the power cars and being sucked through the ventilation to the electronic control cabinets,” the report said.

“It is surprising that the electronic control cabinet does not have a door fitted and is open to the buildup of snow,” the report added.

The review follows a disastrous series of events on Dec. 18 and 19 when the Eurostar trains became trapped in the Channel Tunnel, stranding more than 2,000 passengers for up to 16 hours.

The report said Eurostar was simply unprepared for severe winter weather and that routine maintenance procedures were inadequate, even though the company had had problems in such conditions since 1996.

The report says there must be better crisis communication between Eurotunnel and Eurostar when there is an emergency in the tunnel.

The reviews also said Eurostar needs to do better on informing passengers when delays occur and needs to improve its communications between trains in the tunnel and controllers and emergency services.