The lava at strato volcanoes occasionally forms 'a'a, but more commonly it barely flows at all, preferring to pile up in the vent to form volcanic domes. Some strato volcanoes are just a collection of domes piled up on each other. Strato volcanoes are commonly found along subduction-related volcanic arcs, and the magma supply rates to strato volcanoes are lower. This is the cause of the cooler and differentiated magma compositions and the reason for the usually long repose periods between eruptions. Examples of strato volcanoes include Mt. St. Helens, Mt. Rainier, Pinatubo, Mt. Fuji, Merapi, Galeras, Cotopaxi, and super plenty others.
Although they are not as explosive as large silicic caldera complexes, strato volcanoes have caused by far the most casualties of any type of volcano. This is for many reasons. First is that there are so many more strato volcanoes than any of the other types. This means that there will also be lots of people who end up living on the flanks of these volcanoes. Additionally, strato volcanoes are steep piles of ash, lava, and domes that are often rained heavily on, shaken by earthquakes, or oversteepened by intruding blobs of magma (or all of these). This makes the likelihood of landslides, avalanches, and mudflows all very high. Occasionally as well, entire flanks of strato volcanoes collapse, in a process that has been termed "sector collapse". Of course the most famous example of this is Mt. St. Helens, the north flank of which failed during the first stages of the big 1980 eruption. Mt. St. Helens was certainly not the only volcano to have suffered an eruption such as this, however. Two other recent examples are Bezymianny (Kamchatka) in 1956, and Unzen (Japan) in 1792. The 1792 Unzen sector collapse dumped a flank of the volcano into a shallow inland sea, generating devastating tsunami that killed almost 15,000 people along the nearby coastlines.