Indonesian Volcano, Mount Sinabung, Erupts & Shoots Ash 3 Miles High. Mount Sinabung had been dormant for centuries before first erupting again in 2010 A volcano in Indonesia exploded in spectacular fashion this week, sending a tower of ash flying three miles high ... leaving surrounding villages and communities shrouded in darkness. Mount Sinabung erupted Monday on Indonesia's Sumatra Island, sending a massive column of volcanic ash spewing thousands of feet into the sky 16,400 to be exact. Luckily, no one was killed or seriously hurt from the explosion, but there were warnings of lava flows. This is wild Check out the link to read more about this.