Now Playing: Several people wounded after shooting outside Arkansas graduation

Now Playing: Graduate and his dad killed in mass shooting after high school graduation

Now Playing: New Hampshire Gov. Chris Sununu says he will not run for president

Now Playing: ABC News Live: Dangerous smoke spreads across US from Canada

Now Playing: Parts of the US experiences dangerous air quality from Canada wildfires

Now Playing: Americans experience dangerous air-quality from Canada wildfires

Now Playing: Race for the Republican presidential nomination heats up as 3 more candidates join

Now Playing: Business Headlines: Warning about recalled Bobby products

Now Playing: Race for the Republican nomination heats up as 3 more candidates join

Now Playing: 3 more candidates enter the race for president

Now Playing: Smoke from Canadian wildfires stretches across US

Now Playing: ABC News Live: Dangerous wildfire smoke spreads across the US

Now Playing: NYC mayor says air quality expected to 'deteriorate further'

Now Playing: ABC News Live: 13 states under air quality alerts as Canadian wildfires rage

Now Playing: Millions of Americans experience dangerous air quality from Canada wildfires

Now Playing: Former Vice President Mike Pence announces run for president

Now Playing: Who is Doug Burgum the North Dakota governor running for president? | FiveThirtyEight

Now Playing: PGA Tour faces backlash after announcing partnership with rival LIV Golf

Now Playing: 2 suspects arrested in connection with spate of Houston bike trail robberies

Now Playing: Fights break out at school board meeting over Pride month recognition