Yes, Bert was born on the day Walter died.  One wonders if the shock of Walter's death didn't bring on Sarah's labor.

1.  Allen L. Potts.  Marion County, Ohio, Probate Court Marriage Records, Vols. I-XII, 1824-1902 (online at Heritage Pursuit):

Straub, George W.*	Corbin, Sarah E.	8/5/1866	JP Robert Porterfield
*not 21 cert from his mother giving her consent

2.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

William B. STRAUB Birth: 09 Nov 1873, Marion, Ohio Father: George W. STRAUB; Mother: Sarah E. CORBIN Source: Birth Records, 1867-1908. Ohio. Probate Court (Marion County)

3.  1870 Census Index/Images (online at Genealogy.com; Image #4 of 8):  Waldo P.O., Village of Waldo, Marion Co., OH, Roll 1240 (Book 1), p. 211B, PN 3, 29/32, enumerated 7 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Stroub George W	24	M	W	Carpenter			Ohio
Sarah E	22	F	W	Keeping House			"
Mary G	2	F	W				"
Walter E	8/12	M	W				"

Listed four households from Sarah's parents, Elijah & Elizabeth (ELY) CORBIN; and, in the other direction, five households from Sarah's sister, Martha (CORBIN) BENSLEY. 

4.  1880 Census Images (online at Ancestry.com; Image #5 of 22 — indexed "Strant"):  Incorporated Village of Waldo, Marion Co., OH, p. 123A, PN 5, SD 5, ED 95, enumerator: George W. Straub, actual enumeration date not given, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen):¤•

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

8

9

10

13

14

21

24

25

26

42

45

Straub George

W

M

34

/

Carpenter

3

OH

PA

OH

______ Sarah E

W

F

32

Wife

/

Keeping House

OH

PA

PA

______ Mary G

W

F

12

Daughter

/

at school

3

/

OH

OH

OH

______ William

W

M

6

Son

/

OH

OH

OH

______ Myrtle L

W

F

3

Daughter

/

OH

OH

OH

______ Albert

W

M

1

Son

/

OH

OH

OH

Ironically, given that George was the enumerator, his name actually does look more like "Strant," than Straub.

5.  1890 Census:  the 1890 census population schedules were destroyed.

6a.  1900 Census Index/Images (online at Genealogy.com; Image #4 of 44):  Kenton Avenue, City of Marion (Ward 6, Pct A), Marion Co., OH, Roll 1302 (Book 1), p. 194B, SN 2, SD 12, ED 64, enumerated 4-5 Jun 1900 (extracted by Diana Gale Matthiesen):¤•

1900:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
1	2	3	4	5	6	7	8	9	13	14	15	19	22	23	24
33	33	Straub Geo W	Boarder	W	M	Apri 1846	54	S	OH	PA	OH	Laborer	Y	Y	Y

One of several dozen tenants in a boarding house.

6b.  1900 Census Every-Name-Index/Images (online at Ancestry.com, Image #26 of 33):  229 Vine, Marion City (Ward 4), Marion Co., OH, Roll T623_1302 (Book 1), p. 165B, SN 13, SD 12, ED 61, enumerated 11 Jun 1900, official enumeration date 1 Jun 1900 (extracted by Diana Gale Matthiesen):¤•

1900:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

7

8

9

13

14

15

19

20

21

22

23

24

25

27

*

229

316

330

Peters Andrew J

Head

W

M

Jan 1829

71

Wd

OH

VA

OH

Janitor

0

Y

Y

Y

O

H

______ Jennie D

Dau

W

F

Jun 1859

41

S

OH

OH

OH

Teacher School

3

Y

Y

Y

______ Hattie E

Dau

W

F

Dec 1860

39

S

OH

OH

OH

"

3

Y

Y

Y

______ Allie E

Dau

W

F

Feb 1868

32

S

OH

OH

OH

"

3

Y

Y

Y

______ Harley E

Son

W

M

Nov 1875

24

S

OH

OH

OH

Laborer Farm

4

Y

Y

Y

Straub Josephine

Orphan

W

F

Apr 1881

19

S

OH

OH

OH

At School

9

Y

Y

Y

*Vine

In 1906, Josephine married William J. PETERS, grandson of William L. PETERS, brother of Andrew J. PETERS.

7.  1910 Census Index/Images (online at Ancestry.com, Image #3 of 13):  501 Seventh Street, Oakland City (Ward 6), Oakland Twp., Alameda Co., CA, Roll T624_71 (Part 1), p. 100A, SN 2A, SD 3, ED 132, enumerated 30 Apr 1910, official enumeration date 15 Apr 1910 (extracted by Diana Gale Matthiesen):¤•

1910:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

7

8

12

13

14

15

16

17

18

19

20

21

22

23

24

26

28

*

501

26

28

Revel Henre

Head

M

W

24

S

France French

France French

France French

1905

Al

Eng

Bed Maker

Hotel

W

N

20

Y

Y

R

H

Straub George

Lodger

M

W

61

S

Ohio

Pennsylvania

Pennsylvania

Eng

Gardener

Families

W

Y

22

Y

Y

Cody George W

Lodger

M

W

28

S

Washington

Kansas

Illinois

Eng

Laborer

Odd Jobs

W

Y

16

Y

Y

*Seventh Street

Given his occupation and marital status, I wouldn't have believed this was our subject except for the fact that 1) I don't find him in Ohio and 2) two of his sons are also in Oakland.

8.  1920 Census Every-Name-Index/Images (online at Ancestry.com, Image #31 of 41):  Rudsdale Street, Oakland (Ward 243-245), Brooklyn Twp., Alameda Co., CA, Roll T625_91 (Book 1), p. 261B, PN 16B, SD 5, ED 142, enumerated 13 Jan 1920, official enumeration date 1 Jan 1920 (extracted by Diana Gale Matthiesen):¤•

1920:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
1	2	3	4	5	6	7	9	10	11	12	17	18	19	21	23	25	26	27	28
*	X	164	372	Straub George W	Head	O	M	W	73	W	Y	Y	OH	PA	OH	Y	Carpenter	Home	W
*Rudsdale Street

George must have moved back to Ohio after the 1920 census because his death certificate shows he died in his home town of Waldo, OH.

9.  State of Ohio.  24 Oct 1927 (date filed). Certificate of Death: Geo. W. Straub.  Dept. of Health, Div. of Vital Statistics, Reg. Dist. No. 815, File No. 58943.  Informant: Mrs. D.W. Benedict [nee Mary Gale Straub, dau.], Waldo, OH.

10.  Tombstone of George W. and Sarah (CORBIN) STRAUB, Waldo Cemetery, Waldo, Marion Co., OH:

Photo courtesy of Mark Hross.

STRAUB GEORGE W 1846 - 1927 SARAH CORBIN 1848-1888 To the right is a stone that appears to be for Delbert W. & Mary Gale (STRAUB) BENEDICT, she being the daughter of George & Sarah (CORBIN) STRAUB.

11.  Paul J. & Barbara Midlam.  1985.  Marion County, Ohio, Cemetery Inscriptions:

STRAUB, George W	1846-1927	Waldo [Cemetery]	Waldo
STRAUB, Sarah Corbin	1848-1888 w/o George W.	Waldo [Cemetery]	Waldo

12.  Maxine Marshall, ed.  [nd]  Marion County, Ohio, Death Records, 1867-1880, Volume I.  Marion Area Genealogical Society, Marion, OH (online at Heritage Pursuit; missing columns contained no data):

Name	Death Date	Age	Place of Death	Place of Birth	Cause
STROUB, Walter E.	03/07/79	9Y 3M 27D	Prospect Tp	Waldo	Enlarged Heart

The death of Walter in Prospect explains something I had never understood:  why Bert Straub, Walter's younger brother, was born in Prospect when all of Bert's siblings were born in Waldo.  Having found this death record, I now see that Bert was born the day Walter died.  For whatever reason, Sarah and Walter — plus possibly George and other members of the family — were obviously in Prospect the day Walter died, and that is the day Bert, my grandfather, was born.  Did the shock of Walter's death trigger Sarah's labor?  It would seem so.

13.  Anon.  Tuesday, 16 Aug 1881.  "Ohio Happenings." Marion Daily Star (Marion, OH). Vol. IV, No. 263, p. 4 (online at Ancestry.com):

Mrs. Straub, of Waldo, who has been in the county jail for the past two weeks on account of insanity, is no better, and will be taken to the Asylum at Columbus tomorrow.  Mrs. Straub is about 36, and has been married some fifteen years; has a husband and four children; is a daughter of ex Sheriff E.K. Corbin.

14.  Anon.  Wednesday, 22 Oct 1947.  "Twenty Years Ago." The Marion Star (Marion, Ohio), v. LXX, n. 279, p. 6 (image 8 of 20 online at Ancestry.com):

TWENTY YEARS AGO It was Saturday, Oct. 22, 1927... George W. Straub, 81, pioneer Marion carpenter and building contractor, died at the home of his daughter, Mrs. D. W. Benedict in Waldo...

15.  Anon.  1928.  History of Alameda County, California.  S.J. Clarke Publ. Co., Chicago, IL.  On p. 398, from a biographical sketch of son, William Barton STRAUB: 

...a son of George W. and Sarah (Corbin) Straub... the father... had followed the business of contracting and bridge building...

16.  Interview of my mother, Nina Gale (Straub) Matthiesen, who told me the names of her father's (Albert Roy Straub's) siblings, although she was unaware of Walter E., who had died young.

17.  Email from Mark Hross.