The main volcanic hazard at Mauna Loa is lava flows. Most flows advance at about walking pace and present little danger to human life, but eruptions at Mauna Loa can be more intense than those at Kīlauea; for example, the 1984 eruption emitted as much lava in three weeks as Kīlauea's current eruption produces in three years. Such high emission rates can generate comparatively fast-moving flows.
Two eruptions of Mauna Loa have destroyed villages. In 1926, the village of Hoʻōpūloa Makai was overrun by lava flows. In 1950, the most voluminous eruption ever seen at Mauna Loa sent lava flows racing towards the sea. The village of Hoʻokena Mauka was destroyed on 2 June 1950 by the advancing flows. Hilo is partly built on lava from an 1880 eruption and is at risk from further lava flows. The brief but intense 1984 eruption saw lava flow towards Hilo, but it had not reached any buildings when the eruption stopped.