Two Pennsylvania troopers and a civilian were killed in crash early Monday 

Troopers Martin F. Mack III, 33, and Branden T. Sisca, 29, died along with a man jay walking on the parkway, who they were about to take into custody

They were trying to help a man into the back of a cruiser when all three were hit

The unidentified man, who also died, was walking down I-95 at the time

All three were struck by a woman who had been stopped just moments earlier on suspicion of DUI; The officers left her after getting the call about the man

Two Pennsylvania state troopers and a man were run over and killed alongside I-95 in Philadelphia early Monday morning by a woman who had been stopped on suspicion of driving under the influence just moments before.
Troopers Martin F. Mack III, 33, and Branden T. Sisca, 29, were on the shoulder helping a man into the back of a cruiser when the woman tried to drive past the three men at a high speed just before 1 a.m.
‘The impact was so great that it threw the troopers over into the northbound lanes of Interstate 95.’ Pennsylvania State Police Capt. James Kemm said in a press conference, according to KYW.

Witnesses attempted CPR but all three men were pronounced dead at the scene.   
The woman who struck them had been stopped on suspicion of DUI moments earlier, but officers had to let her go her after they got a call about a man walking down the highway. As they were attempting to put the man into custody, a vehicle traveling at a high rate of speed struck all three men.

A woman tried to pass them but struck all three of them. She had reportedly been stopped by the troopers earlier that night but was left when they got a call about the man walking.
Video from WPVI shows a police cruiser along the divider with its airbags deployed.
A silver SUV with extensive damage to the front sat nearby.  
Police officers rode down I-95 North in a procession Monday morning, hours after the three men died near milepost 18.

After the woman struck the men, the vehicle hit a barrier and continued a short distance before coming to a rest on the highway’s right-side shoulder, authorities said.
Officers had reportedly stopped the woman on suspicion of DUI but left her when they were dispatched to respond to the man walking along the highway. 
It is not clear why he was walking or why he was being taken into custody. His name has not been released as police try to contact his family.
Trooper Mack, 33, joined the state police in November 2014. 
He was a 2006 graduate of Monsignor Bonner High school and went on to attend Albright University in Reading. He was married with two children and lived in Bristol Township, Bucks County. 
Trooper Sisca, 29, joined the force in February 2021. He graduated from West Chester University in 2014
Both troopers spent their entire careers assigned to the Patrol Section of Troop K in Philadelphia.

‘Our department is heartbroken with the tragedy that occurred early this morning in Philadelphia,’ said Commissioner Robert Evanchick in a statement. 
‘We ask our fellow Pennsylvanians to keep the families of our troopers and the pedestrian in their thoughts. This is an extremely difficult time.’
Gov. Tom Wolf ordered all flags in state and public buildings throughout Pennsylvania to be flown at half-staff until sunset Friday in honor of Mack and Sisca.
‘This is a heartbreaking tragedy that occurred while these troopers were protecting and serving,’ Wolf said.
‘This mournful incident is a stark reminder of the risks – and sacrifices – our law enforcement officers undertake every day to keep us safe. My heart goes out to their families and the communities they lived in and served.’
Authorities are not investigating the incident as a DUI.
‘A young driver is potentially facing extremely serious consequences,’ said Philadelphia District Attorney Larry Krasner, according to KYW.