The front of the lahar contained boulders and cobbles that would have crushed anyone in their path, while the slower parts were dotted by fine, sharp stones which caused lacerations. Mud moved into open wounds and other open body parts — the eyes, ears, and mouth — and placed pressure capable of inducing traumatic asphyxia in one or two minutes upon people buried in it. Martí and Ernst state in their work "Volcanoes and the Environment" that they believe that many who survived the lahars succumbed to their injuries as they were trapped, or contracted hypothermia, though the latter is unlikely, given that survivors described the water as warm.