Fire damages high school construction site in Worcester, Mass.

Investigators are trying to determine the cause of a three-alarm blaze that broke out Monday at the construction site of the new Doherty Memorial High School in Worcester, Mass.

The Worcester Telegram & Gazette reports that the school is being built next to the existing 56-year-old Doherty High. The project is about two years away from completion.

The fire sent a massive plume of black smoke over the city that could be seen for miles before it was brought under control by fire crews in about 30 minutes.

A construction worker was treated at a local hospital for non-serious injuries.

Fire officials say roofing material on fire was responsible for sending the thick, dark smoke into the air. The fire was atop metal decking, about five floors up.

The building is one of four under construction on the site.