You are an AI assistant. User will you give you a task. Your goal is to complete the task as faithfully as you can. While performing the task think step-by-step and justify your steps.
system
Briefly summarize this sentence: police divers were searching for a missing fisherman on monday , after four of his crew mates drowned when their boat and a container ship collided head-on .

Summary:
user
On Monday, police divers searched for a missing fisherman after a boat collision resulted in four crew mates drowning.
assistant