Police believe the girls were locked in the trunk from 45 minutes to an hour

WEST VALLEY CITY, Utah (CNN) -- About 1,300 mourners turned out Wednesday for funeral services for five young girls who died of heat stroke after accidentally locking themselves in the trunk of a car Friday.

"I am certain that the Lord, who notes the fall of a sparrow, looks with compassion upon those who have been called upon to part, even temporarily, from their precious children," said Thomas S. Monson, first counselor of the first presidency of the Church of Jesus Christ of Latter-Day Saints, to the families of the girls.

Sisters Jaesha and Audrey Smith, ages 4 and 2, shared the same coffin. Their cousins, Alisha and Ashley Richardson, ages 6 and 3, shared a separate coffin. A 5-year-old friend, McKell Hedden, was in a small casket that was buried next to the other two.

Flags have been lowered to half-staff at government buildings throughout the Salt Lake Valley.

Temperatures in trunk reached 140 degrees

When the girls locked themselves in the trunk Friday afternoon, temperatures in West Valley City, a suburb of Salt Lake City, were in the mid-90s. Temperatures inside the truck were estimated to be as high as 140 degrees, and the medical examiner said the heat could have killed them within 30 minutes.

The girls' deaths, along with two similar tragedies this summer that claimed six more young lives, are generating renewed calls for automakers to install release switches inside car trunks that would allow someone inside to open the trunk lid.

Advocates cite not only the accidental deaths but crimes such as kidnappings.

Janette Fennell of San Francisco became a crusader for trunk releases after she and her husband, Greg, were abducted at gunpoint, robbed and stuffed into the trunk of their car in 1995.

They dug amid the trunk's upholstery, and she found a release cable and then led her husband's hand to it, enabling him to pop the trunk lid for their escape.

"We never found out who did it. Later, the police said, `You know, you are so lucky, because it never ends like this,'" Ms. Fennell said. "That stuck in my mind for months. If it doesn't end like this, how does it end?"

Automakers resist idea of inside releases

Automakers and federal regulators, however, say they are still not convinced that trunk releases are the answer. They could even worsen the problem by signaling to youngsters that it's OK for children to play in trunks, said Kyle Johnson, a spokesman for General Motors Corp.

"It's not really an engineering or cost issue. It truly comes down to being a highway safety issue," said Johnson, who cited studies suggesting that criminals would act more violently if they knew that victims could escape from the trunk.

The Fennells' ordeal inspired them to form the Trunk Releases Urgently Needed Coalition, or TRUNC, in 1996. The group advocates an illuminated or glow-in-the-dark switch.

Cars that have a trunk release lever already have a cable running to the trunk, Fennell said.

"All we're asking them to do is tap into the same cable that's already there," she said.

Switches can be installed for $4

People can install switches themselves for about $4, she advises on TRUNC's Web site.

Critics counter it would be impractical for automakers to install trunk release switches routinely.

The American Automobile Manufacturers Association cites a 1984 study by the National Highway Traffic Safety Administration that concluded "the likelihood of an internal hood latch lever being utilized is remote."

Barry Felrice, AAMA director of regulatory affairs, questioned whether children could even operate a trunk release. Like GM's Johnson, he saw danger in telling children about the releases because they might conclude it was OK to play in the trunk.

Supporters including Rep. Bart Stupak, D-Michigan, tried unsuccessfully for legislation requiring routine installation of trunk latches. Because of his efforts, NHTSA will re-examine the issue.

Fennell said she is upset it has taken so long.

"It's not technology, it's not expensive, and in my mind it's a no-brainer," she said.

The 11 children who died this summer all were 6 or younger, and all suffocated or died of excessive heat.

Two boys in Greensboro, Pennsylvania, died August 2 after using their parents' car keys to get into the trunk. In Gallup, New Mexico, four young cousins died after climbing into an open trunk July 13.

The Associated Press contributed to this report.