BOCA CHICA BEACH, Texas (Border Report) — A fiery explosion followed by a sonic boom rattled the South Texas Gulf Coast during a failed test just before 2 p.m. at SpaceX’s rocket testing launchpad near Boca Chica Beach, Texas.

The SpaceX Starship SN4 prototype exploded on Friday shortly after an engine test. The rocket exploded at 1:49 p.m.

Photo gallery: SpaceX rocket blasts off in historic flight to International Space Station

The blast was like a wave that shot into the sky and took a few seconds to reach onlookers who were watching from Highway 4, about half a mile away. The blast was so loud that cars shook and car alarms went off before construction workers at a SpaceX hangar ran out to a chain-link fence to see what had happened.

Construction workers could be seen outside one of the hangars at SpaceX’s South Texas facility near Boca Chica Beach, Texas. (Sandra Sanchez/Border Report)

Police had closed down the highway to traffic but Border Report had just gotten through the checkpoint 20 miles away en route to film a story in anticipation of Saturday’s planned manned launch in Florida by SpaceX of a crew — the first planned launch of a manned craft from U.S. soil in over a decade.

The flashing emergency lights of emergency crews could be seen immediately after the blast. Thick white and black smoke billowed from the site and it appeared that some type of liquid was being doused on the flame, although that is not confirmed.

The fire burned for about 40 minutes following the blast, which altered the migration of sea gulls and local birds that seemed to jump in the air and were startled by the sight and sound.

Then shortly before 3 p.m. more black smoke could be seen as well as more fire in the area.

SpaceX Boca Chica last had an explosion occur in February when the Starship SN1 suffered a cryogenic explosion.

The explosion at the SpaceX facility near Boca Chica Beach happened at 1:49 p.m. CST Friday.

SpaceX Founder and CEO Elon Musk in 2011 was wooed to South Texas by community leaders who came up with a $30 million incentive package for the company to build the first commercial rocket launch pad in the country in this poor border region of South Texas.

The SpaceX test facility is located on five acres that were donated to the company, which is based in Hawthorne, Calif., former Brownsville Mayor Tony Martinez told Border Report on Friday.

Martinez and others expressed enthusiasm for the economic payoff they believe this company will bring to the region.

“We happen to be geographically located in a perfect spot because you’re right there at Boca Chica and you’re close to the equator, which means this is the route to go to Mars. And this thing hopefully tomorrow will prove as successful as I think it can and be safe for everybody,” said Martinez, who was mayor until 2019.

NASA picks 3 space firms to create human moon-landing systems

Martinez said the City of Brownsville put up $5 million, the State of Texas put in $15 million, 5 acres of land was donated from the nearby port, and the University of Texas Rio-Grande Valley added $10 million to begin a STARGATE program, which stands for Spacecraft Tracking and Astronomical Research facility. That facility is located about one mile from the launch pad.

“It was a community effect of everybody putting into this and that’s the beauty of the deal because evrybody is now invested in this,” Martinez said.

Gilberto Salinas, who was the executive vice president of the Brownsville Economic Development Corporation at the time they were trying to get SpaceX here, told Border Report on Friday that the company created 500 jobs for the region and paid back the $5 million to the City of Brownsville in less than four years. He said the economic prospects the facility brings are as limitless as the stars in the sky.

U.S. Rep. Henry Cuellar, D-Texas, vice chairman of the House Appropriations Border Security Subcommittee, said he added language in the 2019 and 2020 budget bills exempting this South Texas SpaceX site from border wall construction. Originally, U.S. Army Corps of Engineers plans had placed the border wall straight through this launchpad site.

U.S. Rep. Filemon Vela, D-Texas, who represents the Brownsville area, told Border Report on Friday: “America’s innovation and abilities are limitless and are exemplified by NASA and SpaceX’s Demo-2 mission. South Texas is perfectly positioned, as the gateway to space, to cultivate more historic events like this one and the economic opportunities that come along with it.”

Visit for the latest exclusive stories and breaking news about issues along the United States-Mexico border.