July 11, 1973.

It’s described as "the worst night ever" in Worcester’s Main South neighborhood.

Just before 3 a.m., at the back of a rooming house at 728 Main Street, an arsonist sets a fire on the second floor of the five-story building’s wooden porch.

The fire quickly spreads, engulfing the dozens of one-bedroom apartments and the tenants that live in them.

10 tenants died in the fire. 29 people were injured.

It’s the deadliest fire in Worcester’s history, and 50 years later, the arson and murder case remains unsolved.