The incident occurred near FM 528/NASA Parkway.
As of 10:25 p.m., the right shoulder, right lane and center lane are shut down, according to Houston TranStar.
Garza said the crash may have involved a bicycle.
The circumstances leading up to the fatal crash are unknown. No identities have been released at this time.
Traffic alert: Major crash IH-45 Gulf Fwy S/B at FM 528/W Nasa Pkwy. Multiple lanes are shutdown. 1st responders are on location. Seek alternate routes to avoid delays. Possible fatality crash involving a motorcycle. Alternate route: exit Bay Area Blvd. or NASA Pkwy. SB on… pic.twitter.com/CbnHiiNrKM
— Terry Garza, LT (@HCSO_TerryGarza) July 1, 2025