FIRE bosses will investigate the tactics used to tackle a warehouse blaze in which one firefighter died and three others are missing, a senior officer said today.

Warwickshire county fire officer William Brown said he was "deeply shocked" by the "catastrophic" events at Atherstone On Stour, Warwickshire last night.

He said he had "grave concerns" for the missing firefighters, who remain inside the vegetable packing warehouse.

He said: "The whole situation around this incident, the tactics employed by the firefighters while they were there, will be subject to this investigation."

A Fire Brigades Union spokesman said last night's loss of life could be the worst since the 1970s or perhaps even the 1960s.

Although he would not comment on possible causes of the deaths in Warwickshire, he expressed disquiet at the rising toll of recent years.

"We had a long-term downward trend, but that has changed," the spokesman said.

"At this stage we would just say we are concerned about a significant upward movement of firefighter deaths in recent years. It's a major cause of concern for the union."

Firefighters generally die in pairs because of the way they work, he added.

"It tends to be breathing apparatus teams, who work in pairs in the dark in smoke," he said.