A device that appeared to be a hand grenade prompted a partial evacuation and bomb squad response Monday morning at the Veterans Administration West Los Angeles Medical Center.

The bomb squad responded to the hospital in the 11300 block of Wilshire Boulevard at about 7 a.m. after the discovery of the device. A 66-year-old patient brought the item to the emergency room area and claimed to have found a grenade in a bathroom, according to authorities.

Bomb squad investigators determined that the device was "inert."

"It was non-active, but it was made to look like it was active," said Ed Casey, VA police chief. "The subject had placed a copper wire through the thumb break of the grenade."

The man who brought the device to the ER area was detained, and authorities later told NBC4 that he admitted to bringing the grenade to the hospital.

He is under lock down in the hospital's psychiatric ward. Because he did not make any specific verbal threats, he likely will not face any criminal charges.

Federal agents did not find any additional suspicious devices after searching the man's home.

The man told police he kept the grenade as a memento from his military service, authorities said.

The emergency room area was evacuated. The order, involving about 100 people, was lifted about two hours later at 9:20 a.m.

The investigation also led to nearby road closures. Aerial video showed firefighting units and other law enforcement vehicles on the campus, which has its own 72-member police force.

Monday’s incident reignited fears among veterans that security at the campus is getting weak, citing the removal of metal detectors that once stood in the ER entryway.

VA Police Chief Ed Casey said the machines were taken out about a decade ago.

"If there was data to indicate I’m having weapons introduced at a higher rate than normal, I would be asking for those (metal detectors) back," Casey said.

Signs are posted warning veterans not to bring in weapons and security cameras monitor the entrance, along with 72 VA police officers who patrol the campus. Two security guards are stationed inside the ER.

Patients must show identification and if there’s something suspicious about them, they may be searched using a hand-held metal detector.

Many of the veterans NBC4 spoke with on Monday said they are rarely searched when entering the hospital.