A few suggestions for you:
1. Talk to neighbours, or others in the area, who might remember the incident. They might be able to assist in narrowing down the date.
2. See if anyone knows where the family are buried. (That, of course, assumes that they weren't cremated). The gravestones will probably show the dates of death.
3. If your local newspaper can't help, it might be worth trying the regional one. Contact details for the Yorkshire Post are here:
http://www.yorkshiretoday.co.uk/mk4custompages /CustomPage.aspx?sectionID=11052
4. The main reference library for your area will probably retain copies of the local newspapers (possibly on microfiche or digital storage).
5. Local newspapers are also stored by the county record office (Your local library will be able to tell you where this is).
Chris