Heavy incessant rains in Indonesia's Sumatra brought down cold lava and mudslides killing over 40 people | Reuters

Hundreds were evacuated from the flash flood-affected areas including Agam, and Sumatra island. The floods destroyed several houses and bridges leaving many stranded as well. The search and rescue operations are underway | Reuters

What is Cold Lava?

Cold lava also known as 'lahars' in Indonesia, is a mixture of water, ashes and rock fragments that flows down a volcano and enters a river valley. It can travel up to 70-80 km per hour speed | Reuters

According to the United States Geographical Survey (USGS), a large cold lava can carry away almost anything in its path, including buildings and bridges | Reuters

The cold lava that erupted from Mount Marapi in Indonesia is one of the 120 active volcanoes in the country | AP