Ashes are from one quarter to five mm in diameter. Volcanic ash can affect people hundreds of miles away from the volcano. Several of the deaths from the Mount St. Helens volcano in 1980 were caused by inhalation of volcanic ash. Volcanic ash can contaminate water supplies, cause electrical storms, and collapse roofs. .
Cinders are about the size of a golf ball. .
Bombs can be several meters large. However they can be about the size of a golf ball. Volcanic eruptions known as lateral blasts which are sideways blasts can shoot bombs at high speeds for several miles. These blasts have been known to knock down entire forests . Volcanoes can also trigger tsunamis, floods, earthquakes, rockfalls, and mudflows.