Boston and Newton Firefighters responded to 2635 Beacon Street in front of Boston College for a Level 3 Hazardous Materials Incidents. A 24' box truck carrying assorted flammable gases including hydrogen, propane and chlorine tanks. The operator smelled what he believed to be chlorine and pulled his truck over calling 911. Two buildings at Boston College and several homes in the area were evacuated as a precaution. No injuries were reported and the Boston FD Haz Mat Team was able to secure the leak.