Uses: A Fire extinguisher: (2) Surface coating: It is possible to coat an object with a fire retardant. The classic example of this is the green Christmas tree. As a tree dries out it can be accidentally lit on fire putting the home at risk. A coating of a specialised fire retardant can prevent the starting of the fire and slow it down if it does start. In addition many large sky-scrapers use a coating around main structural elements to prevent catastrophic weakening during a fire. It is believed that one of the reasons why the twin towerscollapsed on 9/11 was due to the airplane impact removing portions of the fire-insulation layer. Many dormitories across the nation are also considering using these products. Since 2000, 109 people have died in fires in dormitories or off-campus student housing across the nation, according to Campus Firewatch, an online newsletter. Campus Firewatch's publisher, Ed Comeau, said a January 2000 fire at Seton Hall University in New Jersey drew attention to the perils of fire on campus. A common area in a Seton Hall dorm caught fire after two students ignited a banner from a bulletin board. The fire quickly spread to furniture and killed three students and injured 58 others