At least two people died Sunday in an explosion and partial collapse of a four-storey residential building in northern France, media reports quoting the fire department said. At least 10 people were injured and other people were trapped in the rubble in Reims in the Champagne region, the BFM TV news channel reported. According to dpa, a gas leak was believed to be the cause. "The explosion was extremely strong because it shattered the windows in the buildings in front of it," Mayor Adeline Hazan told the channel.