It wasn’t the cold, but vandalism, that forced a two-hour late start of classes this morning at a northeast Iowa school district. Independence school officials say during the night, someone unplugged all the district’s buses. The vehicles, which run on diesel, all froze up in sub-zero temperatures and wouldn’t start this morning. District transportation officials discovered the vandalism when they arrived for work today. They immediately began thawing the buses out in an attempt to get them running. District officials reported the vandalism to Independence police. The crime is under investigation.