The lockdown at Naval Air Station Joint Reserve Base in Fort Worth has been lifted.
A spokesperson at the NASJRB said the hour-long lockdown was caused when an unauthorized vehicle drove onto the base.
Petty Officer Second Class Nathan Gomez told The Dallas Morning News that a white Ram pickup truck drove through a security gate at 3 p.m. on Wednesday.
Shortly after that, all gates were closed.
At 3:30 p.m., the inbound lanes were reopened, but every vehicle will be searched before leaving the base.
The lockdown was lifted at about 4:30 p.m.
Officials are investigating.