Emergency services: At least 14 ambulances and five units of the fire brigade rushed to the crash scene after the major emergency plan for Meath was activated.
The plan, co-ordinated by the Meath county manager, was activated within a short time of Meath County Council receiving a call at 4.28pm.
Kevin Stewart, director of services with the county council, said a 999 call had been received at a central control room in Tara Street, Dublin, which automatically alerted the nearest fire brigades, in Navan and Ashbourne, as well as the Garda and ambulance services.
He said the first unit of the fire brigade on site immediately alerted Drogheda and Dunshaughlin fire services.
The officer in command of the fire service at the site also decided the county's major emergency plan should be activated, he confirmed.
"The activation of the emergency plan involves setting up an incident room, ensuring the various services that need to be alerted have been and are on site, and they would include fire services, having traffic diversions in place, and getting equipment like cranes to the scene," he added.
The incident room received many calls, and staff answering phone-calls were overwhelmed by the generosity of people who called in to offer to help in any way they could. Many had offered to provide counselling to those who might need it, he said.
The five fire brigade units came from Navan, Ashbourne and Drogheda. A unit from Dunshaughlin was mobilised but was not required, he said.
The Health Service Executive (HSE) for the north east region said 14 emergency ambulances attended the scene. These included a number from the Dublin region.
The Northern Ireland ambulance service provided standby cover for other emergencies in the northeast.
A total of 26 patients were brought to Our Lady of Lourdes Hospital in Drogheda. Six were said last night to be in a critical condition, while others were still being assessed, the HSE said.
Another 27 patients were taken to Our Lady's Hospital, Navan, some by ambulance and others by private transport.
A counselling service was set up at both hospitals.
The Department of Defence provided four air corps helicopters, three Alouettes and one Gazelle, to assist in the rescue operation.
They were used to transport doctors to the scene but were not required to transport the injured, who were taken to hospital by ambulances, taxis and private cars.
While it was initially expected that some of those injured would be taken to Dublin hospitals, this did not happen, the HSE said.
Meanwhile, the chairman of the Government task force on emergency planning, Minister for Defence Willie O'Dea, who visited the crash scene last night, ordered the cancellation of two simulated major emergency planning exercises scheduled to take place today in Maynooth and tomorrow in Sligo.