what were the damages incurred?
The ash fall created some temporary major problems with transportation, sewage disposal, and water treatment systems. Visibility was greatly decreased during the ash fall, closing many highways and roads. Interstate 90 from Seattle to Spokane was closed for a week and a half.
1980 eruption of Mount St. Helens
The ash fall created some temporary major problems with transportation, sewage disposal, and water treatment systems. Visibility was greatly decreased during the ash fall, closing many highways and roads. Interstate 90 from Seattle to Spokane was closed for a week and a half. 
what day of the week was may 25 2008 UNANSWERABLE what led to this eruption? It initiated as a series of phreatic blasts from the summit then escalated on May 18, 1980, as a major explosive eruption. how was the climate that time? As May 18 dawned, Mount St. Helens' activity did not show any change from the pattern of the preceding month. The rate of bulge movement, sulfur dioxide emission, and ground temperature readings did not reveal any changes indicating a catastrophic eruption
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1980 eruption of Mount St. Helens [SEP] Ash damage and removal
The ash fall created some temporary major problems with transportation, sewage disposal, and water treatment systems. Visibility was greatly decreased during the ash fall, closing many highways and roads. Interstate 90 from Seattle to Spokane was closed for a week and a half. Air travel was disrupted for between a few days and two weeks, as several airports in eastern Washington shut down because of ash accumulation and poor visibility. Over a thousand commercial flights were cancelled following airport closures. Fine-grained, gritty ash caused substantial problems for internal combustion engines and other mechanical and electrical equipment. The ash contaminated oil systems and clogged air filters, and scratched moving surfaces.