Bermuda re/insurer Endurance Specialty Holdings Ltd has estimated losses of between $45 million and $55 million from last month’s tornadoes in some southern states of the US.Most of the losses came in the company’s reinsurance book and related to reinsuring regional homeowner and farm mutual insurance companies in the US.The initial loss estimate is pre-tax and net of reinsurance and reinstatement premiums.Catastrophe modeller Risk Management Solutions (RMS) has estimated the tornadoes, which struck between April 25 and 28 and killed more than 200 people, may cost insurers about $6 billion, with 70 percent of the claims likely to emanate from the state of Alabama.April 28 was the deadliest single 24-hour period for US tornadoes since 1974, according to AccuWeather.Last month, about 305 tornadoes touched down during the outbreak, more than twice the April average of 161, RMS said.The biggest insurance loss from convective storms in the US was $3.2 billion in May 2003, according to the modelling firm, which has value equal to $5 billion in today’s money, it said.