SIOUX FALLS, S.D. (KELO) — Tuesday the Sioux Falls Police Department’s reconstruction team shut down the sight of Saturday’s deadly crash near Dawley Farm Village.

The late-night crash killed two Sioux Falls students and sent two teenagers to the hospital. They were in a car that police say was struck by a speeding driver who ran a red light on Arrowhead Parkway. Both people in that vehicle also went to the hospital.

Even though investigators have video of the east side crash from a city traffic camera, they still have a lot of questions to answer.

The accident reconstruction team is mapping, plotting and surveying the scene where two people died on Saturday night.

It’s specialized training that uses time-honored scientific techniques now enhanced by modern technology.

“They look at the damage done to the vehicles, the distance that they moved, the pieces that flew off, how far they went, there is a lot of little things that they are looking at,” Sam Clemens with Sioux Falls Police said.

All those little things, add up to a big picture. All sorts of questions will be answered. They can determine how fast the vehicles were going, did the driver hit the brakes before impact, was the driver in the proper lane, were the occupants wearing seat belts.

Sgt Travis Olsen says accident constructionists go through a lot of schooling to become proficient.

“Frankly math is a must in this case, what they do when they have a crash like that is they actually determine things like how much drag is on the roadway to slow a vehicle down, how far the vehicle traveled post impact to help them determine how fast that vehicle was going at the impact and things like that so it’s a vast amount of physics and algebra that goes into it,” Olsen said.

Hours spent kneeling on the ground with chalk and a tape measure have been replaced by technology.

Patrol officer Dirk Anker is part of the UAV team, which was formed about a year ago. Today they had 3 separate drones in the air.

He says the aerial footage they can provide the accident reconstruction team helps them piece together the entire scene.

“It’s a good tool for us to use, we are able to get different vantage points when we fly obviously, just like when you use a computer, Google Maps similar, you’re able to get that birds-eye view, which is really important for people to be able to see it helps people to relate what’s going on,” Anker said.

In a crash this complicated it will take weeks for the report to be finished and sent on to prosecutors for their consideration in whether or not to file any charges.