In Italy, magistrates ordered autopsies on the bodies of the two drivers and revealed that Imola's Autodromo Enzo e Dino Ferrari was being placed under judicial sequestor for investigations into possible criminal proceedings. They also sequestered the drivers' cars and confiscated all available film of the accidents.
Brazilian diplomats had hoped to fly Senna's body home to Sao Paulo yesterday, but said: 'Italian legal and bureaucratic procedures' had delayed the release of the corpse. They hoped to be given clearance today.
Ratzenberger crashed during qualifying on Saturday, and Senna in Sunday's race. Both sustained severe head injuries. The first Formula One fatalities for eight years has stunned the sport and provoked demands for a reappraisal of safety standards.
In a statement, FIA said: 'The FIA is gathering reports from its technical, medical, safety and supervisory staff, as well as from the relevant team and circuit personnel. As soon as these reports are received, they will be studied as a matter of urgency.' FIA said they had called a meeting to review the events at Imola on the request of the Italian Automobile Club.
The statement went on: 'Only when all the facts are known will it be possible to determine if the additional safety measures introduced in 1993 and 1994 need to be extended, those already agreed for 1995 brought forward, or whether further measures should be introduced.'
The authority contended that regulations introduced this year, abolishing 'driver aids' such as active suspension and traction control, did not contribute to the weekend's tragedies. That opinion was echoed last night by the McLaren-Peugeot driver, Martin Brundle, who said: 'I can't see that the regulations had anything to do with those accidents, or the one Rubens Barrichello had on Friday. But I'm very confused.
'I don't know why we are having so many accidents. We have been so lucky for so long. You can't legislate for bizarre shunts, but when Formula One loses the main man, you have got to have repercussions.'
Brundle suggests the driver should have a lower seating position, with padding on the inside of the cockpit. He said: 'This is what they have in IndyCars. The head and neck have become a major area of concern in Formula One and we must try to limit the movement of the head.'
The Englishman also urges changes to some of Formula One's more precarious corners, including Tamburello, where Senna crashed and many other drivers have had appalling accidents. Nelson Piquet and Gerhard Berger are among those who have survived after smashing into that unforgiving concrete wall.
Richard West, the commercial director of the Williams team, said there was no evidence that mechanical or human failure caused Senna's crash. 'There are a number of people we want to talk to who were either on the track as other drivers or in the capacity of officials and marshalls. It's only when we are sure we have all the information possible that we can really start to create some form of solution.'
' We must follow the procedures of speaking to everybody concerned, returning the car here and looking long and hard at all the information we can possibly amass.'
Video film will be studied and the car's black box - which records information about the behaviour of the engine, gearbox and suspension - may also provide important data. West added: 'The box doesn't provide answers in the way a flight recorder does. It will only help in the process.'
Williams maintain it is in no hurry to replace Senna, though speculation has inevitably begun. Among the names being mentioned are Nigel Mansell, Riccardo Patrese, David Coulthard, the team's test driver, and Alain Prost, who left Williams at the end of last season, to be replaced by Senna.
Prost may be willing to step forward into the role of drivers' leader. Speaking before the race, Prost said: 'For many years, when I was driving I was trying to get the drivers together to talk safety, but many, still active, didn't want to listen. But something should have been done and needs to be done.'
A spectator was reported to be in a deep coma with massive bruising to the brain in hospital in Bologna yesterday as a result of another crash, at the start of Sunday's race, when he was hit by a wheel.
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