SEATTLE >> A 3-year-old boy fatally shot himself with a gun he found in a car while his family stopped for gas early Wednesday, police said, marking western Washington’s third recent shooting by a child.

"It is incredible in light of the other ones," said Tacoma police Officer Naveed Benjamin. "You would think people would take more care, not less."

The family was traveling and had stopped at the Tacoma gas station off Interstate 5 at about 12:30 a.m. The man put his pistol under the seat and got out to pump gas while the boy’s mother went inside the convenience store, Benjamin said.

They left her son and her boyfriend’s 4- or 5-year-old daughter in the car, Benjamin said. The boy climbed out of his back-seat child seat, found the gun and shot himself in the head, police said. He was declared dead at a hospital. The girl was not injured.

Detectives questioned the parents and have called the shooting a tragic accident, Benjamin said.

The investigation was continuing, and it was unclear if the man would face any charge. Washington does not have a law specifically concerning child access to firearms.

The family has not been identified. They are not from Tacoma and their car has Oregon plates, Benjamin said.

The shooting follows the death of the 7-year-old daughter of a Marysville police officer in Stanwood on Saturday when a sibling found a gun and fired while the parents were out of their car. And on Feb. 22, an 8-year-old girl was critically wounded in a Bremerton classroom when a gun fired inside the backpack of a 9-year-old boy as he put it on a desk.

"It’s another tragedy in a very short period of time," Benjamin said.

It highlights the need for people to secure guns, he said.

"You can’t predict what children are going to do," he said. "You need to unload and lock it up if you’re not carrying it. … It’s really not that hard to practice firearm safety."

Twenty-seven states have some form of law to prevent child access to firearms. Such laws can include criminal penalties for adults who allow children to get their hands on guns, but Washington is not one of those states, according to the San Francisco-based group Legal Community Against Violence.

State lawmakers considered a measure in the regular legislative session that ended Friday that would have required additional testing of gun locks and safes before the equipment is distributed to law enforcement officers for home use. The bill was prompted by the 2010 death of a Clark County deputy’s 3-year-old son. The toddler took a gun from a department-issued safe, which the family insisted was faulty.

On Saturday, off-duty Marysville police Officer Derek Carlile had parked the family van near Stanwood City Hall, and he and his wife were out of the vehicle when one of their children found the loaded gun and fired. The shot hit 7-year-old Jenna Carlile, and the girl, the oldest of their four children, died Sunday at a Seattle hospital.

The 8-year-old Bremerton girl, Amina Kocer-Bowman, remained in serious condition at Harborview Medical Center in Seattle after nearly dying in the accidental shooting at Armin Jahr Elementary, where the other student brought a handgun to class. Authorities believe the boy took the .45-caliber gun from the glove compartment of a car while visiting his mother and her boyfriend at their home. He lives with an uncle.

The 9-year-old classmate pleaded guilty last week to reckless endangerment and was sentenced to probation and counseling. He is expected to testify against his mother, Jamie Lee Chaffin, and her boyfriend, Douglas L. Bauer, who were charged Tuesday with felony assault.

Chaffin and Bauer each could face up to five years in prison if convicted.