 St Peter 's Field was a croft ( an open piece of land ) alongside Mount Street which was being cleared to enable the last section of Peter Street to be constructed . Piles of brushwood had been placed at the end of the field nearest to the Friends Meeting House , but the remainder of the field was clear . Thomas Worrell , Manchester 's Assistant Surveyor of Paving , arrived to inspect the field at 7 : 00 am . His job was to remove anything that might be used as a weapon , and he duly had " about a quarter of a load " of stones carted away . 
