France's first official investigation into why thousands of elderly people died during a brutal summer heat wave partly blamed hospitals, which let doctors leave during August vacation, according to a report released Monday.

The report also said that health authorities were too slow to realize how serious the situation was in emergency rooms.

The government had said that 11,435 people died in the heat wave that pounded France (search) in early August, when temperatures soared up to 104.

Many victims were elderly, dying alone at home or in overwhelmed hospitals and nursing homes. France's death toll was far higher than anywhere else in Europe (search).

Some critics have also blamed the deaths on understaffing at retirement homes and hospitals, August vacationers who left elderly relatives unattended and government inaction.

Health Minister Jean-Francois Mattei (search) had ordered the report from a team of specialists that included prominent doctors in gerontology, emergency medicine and epidemiology.