WASHINGTON — A pair of nitrogen tanks at Space Exploration Technologies Corp.’s (SpaceX) rocket test facility in McGregor, Texas, exploded late Nov. 26, according to local authorities.

“Anyone that heard the loud boom and felt a rumble outside of McGregor can rest easy,” the McLennan County, Texas, Sheriff’s Department wrote on its Facebook page Nov. 26. “It was two nitrogen filled tanks that over pressurized and ruptured at Space X. Sources are saying no one was injured.”

In a Nov. 27 email, SpaceX spokeswoman Emily Shanklin said the event, “likely the result of over-pressurized gas,” took place at about 10:30 p.m. local time. She confirmed nobody was hurt. The equipment SpaceX was using at the time of the explosion was for slosh-baffle testing, which involves placing structures inside of liquid-filled tanks to control fluid movement.

“SpaceX teams continue work today on site as planned,” Shanklin said. “SpaceX will identify root cause of the incident and make any adjustments necessary to avoid this kind of disturbance to the McGregor community going forward.”

The SpaceX Falcon 9 v1.1 rocket that will be used to launch Thailand’s Thaicom 6 satellite has undergone testing at McGregor but was not at the site when the explosion occurred. The rocket had already been shipped to Cape Canaveral, Fla., in preparation for a scheduled Dec. 20 launch, Shanklin wrote. 

The explosion startled some nearby residents, who registered their surprise in Facebook posts of their own, and in comments below the sheriff’s post.

“I think I just felt my first earthquake!” Duane Price-Hannah wrote before reading the sheriff’s report. “You never know because we live close to SpaceX and also feel things when Fort Hood is playing in the field. This one scared me and was different!”

“I honestly thought it was Ft. Hood practicing a big bomb,” said a post by Kisha Hornung.

Not everyone was fazed by the explosion.

“[Two] miles away from it and slept right through it,” Shane Druppal wrote in a Facebook comment below the sheriff’s post.

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Dan Leone is the NASA reporter for SpaceNews, where he also covers other civilian-run U.S. government space programs and a growing number of entrepreneurial space companies. He joined SpaceNews in 2011.Dan earned a bachelor's degree in public communications...