A car crash in Thornton last night killed a family of five, a relative said this morning.

Witnesses told Thornton police last night that a woman in a Ford Expedition with two children was speeding and driving erratically as she headed south on Grant from at least East 88th Avenue to East 84th Avenue about 5:50 p.m.

Shortly before reaching the intersection, she swerved into the northbound lane and clipped the rear of a Mazda DX sedan.

Her sport utility vehicle struck a raised median and went airborne, landing directly on top of a small Chevrolet S-10 pickup.

Four bodies were found in the crushed pickup immediately after the crash. As firefighters tried to move the twisted wreckage just before 10 p.m., they found a fifth body.

After landing on the truck, the Expedition rolled across a parking lot onto its side and through the front of an Urban Mattress store, as employees and the owner ran for cover. One person inside was injured by flying glass.

A relative of the crash victims came to the site this morning.

Alejandro Aldaco said the people killed in the truck were his 31-year-old niece, her husband and their three sons. He said the oldest boy is 13 or 14. The couple had been high school sweethearts.

He didn’t want to give their names, but a family friend identified them as Randy and Crystaldawn Stollsteimer. Their sons were Sebastion, 12; Darrian, 8; and Cyrus, 6.

“I just wanted to see it for myself is why I came down,” Aldaco said.

Aldaco said his sister is the mother of the woman who was killed in the pickup.

The victims were “were just doing the day-to-day, living life,” he said.

He said the family liked to play Wii and do karaoke together. He added that they had just bought the truck.

Other people came to the crash scene this morning, as well, some taking pictures of the police tape that marked the spot and the broken glass that still littered the street.

The growing memorial included stuffed animals, a pinwheel, five white ceramic crosses and a pair of tall glass-encased candles.

“No matter what, their kids came first and they stuck together as a couple,” said Devon King, a family friend, said while clutching a shard of glass.

Jennifer Romero, a cousin of Crystaldawn Stollsteimer, came with her daughter Victoria Tolmich, 13, and son Manuel Tolmich, 10.

Manuel brought a Scooby Doo toy to leave.

Romero says her cousin and the three boys were at their house for a birthday party just a few weeks ago. She was still in disbelief over the news.

“It couldn’t be true. I still don’t want it to be true,” Romero said.

Dezirae and Paul Valenzuela brought their son Paul, 12, who was friends with Sebastion.

Paul was supposed to go with Sebastion to a regional basketball tournament in a few weeks.

Paul left flowers where his friend died. He said he felt “just sadness.”

The Urban Mattress store was boarded up overnight.

All morning the owner, Paul Roggow, came out of his store to greet and console each person who stopped by.

In southeast Denver, a man believed to be the father and grandfather of the victims answered the door of his home this morning but declined to talk. Dressed in a t-shirt and jeans, he trembled as he said the victims were his family, but he was too disturbed to talk further.

Investigators are reconstructing the fatal crash, said Matt Barnes, a Thornton Police Department spokesman.

Part of the investigation includes toxicology report results on the driver of the Ford Expedition, identified as Monica Chavez, 33. She is still in the hospital, along her two children who were also in the SUV, a 6-year-old boy and and a 10-year-old girl.

“This is very tragic,” Barnes said.

He did not have further details on their injuries.

Barnes said the driver of the Mazda was still in the hospital. He was identified as Victor Omar Madrid-Martinez, 47, of Denver.

Aldaco said it was hard to understand that his relatives were gone so fast.

“It’s just amazing how many things had to happen — a couple of seconds …”

“How does something like this happen,” Aldaco asked rhetorically, “that a person can get so out of control that they don’t pay attention at all to what they are doing?”

He added: “They just took out a whole family.”

Staff writers Monte Whaley and Joey Bunch contributed to this report.