A volcano erupted just north of the town of Grindavik in southwest Iceland on Sunday, just hours after its 4,000 residents evacuated. “No lives are in danger, although infrastructure may be under threat,” Iceland's President Gudni Johannesson said in a post on X. In the past few weeks, Icelandic authorities erected rock and earthen barriers to stop the lava flow from reaching Grindavik, but the eruption appears to have already breached the town's defenses. The Icelandic Meteorological Office (IMO) reported that a fissure had opened in the barriers, and the lava flow had come within an estimated 1,500 feet of the town. The IMO estimated that the lava could reach the town in a matter of hours. The eruption was the second in less than a month in the Reykjanes peninsula, an area that includes the nation's capital Reykjavik and its main international airport, although no flights have been interrupted yet. The nearby Blue Lagoon, a geothermal spa and popular tourist destination, has been closed temporarily.