AUSTIN (KXAN) — On Tuesday, a fatal crash involving a pedestrian that killed one person caused a long closure on Interstate 35 during many people’s morning commutes.

The road was closed for several hours for the Texas Department of Public Safety to investigate the crash. DPS Sgt. Deon Cockrell said the amount of time needed to investigate a crash depends on the size of the crash, location and availability of a crash reconstruction team.

Sometimes an agency will mark the scene and come back the next day for crash reconstruction, especially if it is a busy road and officers are at risk of being hit, Cockrell said.

Fatal accidents require crash reconstruction teams. These include specially trained officers who use drones and special equipment to investigate.

Austin Police, Travis County Sheriff’s Office, Williamson County Sheriff’s Office and other larger law enforcement agencies have accident reconstruction teams, Cockrell said. However, a county or DPS will likely take the lead in investigating fatal crashes in rural areas. Smaller police departments do not always have the tools or teams to investigate these cases.

DPS’s Region 6B team, which works in Austin, has eight to 10 certified troopers who work on reconstructions. There is also one commercial-certified officer on the team who helps with crashes involving semi-trucks or other commercial vehicles.

Typically the agency that arrives first at a scene takes the lead on the investigation, which is based on jurisdiction, Cockrell said.

Cockrell recommended checking traffic conditions before leaving home to avoid crash areas. He said people should have alternate routes planned.

Austin Transportation Department is reporting 49 traffic fatalities this year, per its Vision Zero dashboard. This is up 45 fatalities from this time last year.

KXAN reached out to APD to learn more about its fatal crash investigations. This article will be updated if we receive information.