Billings City officials are cautioning the public that they believe that the rock slide that damaged a home and crushed a truck on Tuesday might not be safe yet. City engineers are monitoring multiple areas for potential instability and believe that more rock could fall in the area. Geotechnical experts from Terracon have completed an initial assessment, the results of which confirmed the belief that there is instability in adjacent areas of the rock face. A deeper investigation is reportedly ongoing and any plan of action will have to wait until that assessment is complete. Q2 reports that Terracon has worked with the city in the past on issues surrounding the rims, including the 2014 slide that closed a portion of Zimmerman Trail. The Billings Fire Department has asked residents of two homes close to the slide area to evacuate.