Complex sentence: The remaining tenants' leases were terminated in early 2005; by February of that year, the entire complex was closed, as its owners decided that electrical costs were too high to keep the largely vacant complex open.
Split into simpler sentences: The remaining tenants' leases were terminated in early 2005. By February of that year, the entire complex was closed, as its owners decided that electrical costs were too high to keep the largely vacant complex open.