Editor’s Note: This article has been updated with a TV news report.

BROWNSVILLE, Texas (ValleyCentral) – SpaceX testing left South Padre Island residents feeling shaken up Monday afternoon.

An explosion during SpaceX’s planned booster (BN7) testing was heard and felt by South Padre Island residents around 4:20 p.m.

The testing involved 33 Raptor 2 engines, each capable of several hundred tons of thrust.

The explosion was seen on live streams during the testing. It is not yet known whether the explosion was a planned result of the testing.

SpaceX CEO, Elon Musk, responded on Twitter saying that the the blast was “Booster engine testing.”

Road closures for the testing began early Monday morning, as per alerts sent by Cameron County.

South Padre Island resident, Michael Sularz, told ValleyCentral that the blast “felt like a truck rammed into [his] home.”

Sularz lives with his family near Blackbeards’ on SPI and says his neighbors felt the “earth-moving boom” as well.

“Made my legs go up while on the sofa. We ran outside thinking we’d see a road accident,” said Sularz.