Here is some info gleaned from TX Dth Idx Online and SSDI.
Floyd J. West b 29 Apr 1907, d 2-8-1974 in Denton Co, TX, last residence Denton, Denton Co, TX - Single - and SS card issued in TX
On TX Dth listed as Addie Whitfield, on SSDI listed as Myrtle Whitfield, b 21 Apr 1909, d 4-17-1998 in Collin Co, TX, last residence Van Alstyne, Grayson Co, TX, and SS card issued in TX
Dewey West b 4 Mar 1911, d 5-29-1977 in Dallas Co, TX, last residence Dallas, Dallas Co, TX, and SS card issued in TX
On TX Dth listed as Ila Estell Riggs, on SSDI listed as Estell Riggs, b 23 Aug 1912, d 1-13-1992 in Smith Co, TX, last residence Grand Saline, Van Zandt Co, TX, and SS card issued in TX
You might look for obituaries for these people, survivors might be listed.Check GenWeb sites for all those counties, some GenWeb counties are putting their cemeteries online.Post queries on those sites, too.
Since Horace died in a farming accident, there should be something in local newspaper about the incident, might mention widow and children, too.If you don't have exact date of his death, visit the Wilbarger Co, TX GenWeb site, if cemeteries not online, post a query, ask if a collection of records, or local cemeteries has been published.Check to see if they have a volunteer who will do lookups, not research, and would check for Horace.Here is hyperlink for TX GenWeb, scroll down to County Index option, click on letter for your county.Counties vary on info and material offered, just click and check out everything.They are growing, so might want to check back from time to time. http://www.rootsweb.com/~txgenweb/http://www.rootsweb.com/~txgenweb/