This activity is a short engineering design challenge that can be completed by individual students or small teams. It can be done by students of all ages, although upper elementary school and above is best. The idea is to present a real-world problem, designing buildings for hurricane-prone areas, but in a simulated way that works in a classroom, after school club, or informal education setting. Students are given simple materials and design requirements, and must plan out and build a tower as tall as possible that will hold up a tennis ball while resisting the force of wind from a fan. For an extra challenge, a spray bottle can be used to simulate rain.  After the towers are built, the group comes together to test them. This is also an opportunity to discuss how there are often different ways to solve the same problem. If there is time after testing, which can be observational or framed as a contest between teams, students can redesign their towers to improve their performance, or simply discuss what worked well and what didn’t in their designs. Depending on how much time you give students to design and build (and possibly rebuild), this activity could be completed in as little as half an hour or up to an hour or more.