Schools could face fines of up to pound;1million under a new offence of corporate manslaughter, coming into force in April.
Heads' leaders have described the development as "bad news".
The Corporate Manslaughter Act, passed last year, creates a new offence for organisations guilty of what the Ministry of Justice describes as "a gross failure in the way activities were managed or organised" that leads to a death.
That includes public sector organisations such as schools - where the governing bodies would be legally responsible. Local authorities could also be responsible in cases where they employed the school staff and a death arose from a gross breach of their duty of care.
The Government's Sentencing Advisory Panel has recommended fines of between 2.5-10 per cent of an organisation's annual turnover.
John Dunford, general secretary of the Association of School and College Leaders, said the largest secondaries had budgets of around pound;10million, raising the prospect of seven-figure fines.
"If a fine wiped out 10 per cent of a school's resources for a year, that would be a disaster which would take a school a long time to recover from," he said. "This is bad news."
But Graham Clayton, the National Union of Teachers' senior solicitor, said: "Governing bodies need to be aware of this and look out for it. But I don't think there is a high likelihood of a rush of prosecutions, however tragic the circumstances may be."
The first ever successful UK prosecution for corporate manslaughter, in 1994, did involve a school and followed the death of four teenagers from Southway Comprehensive in Plymouth, during a canoeing expedition in Lyme Bay, Dorset.
But it was Active Learning and Leisure, the company that organised the trip, rather than the school, that was prosecuted and fined pound;60,000.
Schools, under the new law, could also be punished by "publicity orders", which would require them to own up to their responsibility for a death in a prospectus or on their website.
FE Focus, page 1.