Complex sentence: The channel closed on March 31st, 2003, but before that came the final film broadcast on the channel, the 1981 neo-noir "Body Heat" at 21:45.
Split into simpler sentences: The channel closed on March 31st, 2003. At the end of that day came the final film broadcast on the channel, the 1981 neo-noir "Body Heat" at 21:45.