Scroll to the bottom of this post for updates.

Hit-and-run drivers claimed the lives of two cyclists in San Francisco yesterday, following collisions in Golden Gate Park and SoMa on Wednesday evening.

According to the San Francisco Police Department, the first collision occurred at 6:01 p.m., when a man in his early 20s driving a white Honda Fit fatally struck a cyclist near John F. Kennedy Dr. and 30th Avenue in Golden Gate Park.

Though police did not provide any details on the victim, saying they were "unknown" in an email sent Thursday morning, according to ABC 7 the cyclist was female.

ABC 7 reports that "Paramedics worked frantically to save the woman's life as she lay in the road in Golden Gate Park, her twisted bicycle lay nearby." CBS 5 reports that the victim was rushed to the hospital, but did not survive.

Witnesses told ABC 7 that two men were in the Honda Fit driven by the suspect, who was "going 50 or 60 miles an hour and passing other cars."

"They clearly went into the opposite direction traffic," a witness said, "and went far enough over to run right into that lady head on."

KRON 4 reports that the Fit was discovered, abandoned, near the scene of the collision. ABC 7 reports that the car had dealer plates, and had not been reported as stolen.

The second collision occurred at 8:24 Wednesday evening, at 7th and Howard Streets in SoMa. Though police said in an initial email that the cyclist struck in this case was male, they sent out an update saying that details on the victim were, as with the previous case, "unknown."

KRON 4 reports that the driver in this case "ran a red light and hit the cyclist, and then sped away."

The cyclist was transported to San Francisco General Hospital, but was pronounced dead on arrival.

Police confirm that the suspect, a 32-year-old man driving a BMW X-3 with California plates, was arrested at the scene. According to Reddit user "maurin14," he or she "chased [the suspect] down with another pedestrian and demanded he sit and wait for the police, he obliged. Definitely not sober." An SFPD spokesperson could not confirm this account of the incident.

That spokesperson was also unable to provide the suspect's name and booking information as of publication time. However, we should expect more details on the collisions this morning, as according to a press release sent by the SFMTA, at 10 a.m. today "Mayor Ed Lee, SFPD and SFMTA will hold a media availability to discuss the most recent details about last night’s fatal bike collisions and the city’s ongoing Vision Zero initiative to eliminate traffic fatalities," they say.

Lee will be joined by SFPD Commander Robert O’Sullivan and SFMTA Director Ed Reiskin at the press event, which will be held at the SFMTA Headquarters at 1 South Van Ness Avenue.

Update: Additional information has become available following this morning's press conference. Hoodline reports that in the case of the Golden Gate Park hit and run, the 2016 Honda Fit turns out to have been stolen after all. The abandoned car was reported by a passerby who noticed it was extensively damaged and called police. The suspect (or suspects) in that fatal crash is still at large, and police ask that any witnesses call (415) 575-4444. The victim, whose identity has not been released, was a woman in her late 40s.

In the case of the SoMa hit and run, police confirmed that the driver ran a red light and fled the scene after striking the cyclist. SFPD Commander Robert O'Sullivan said charges in that fatal crash will include felony hit-and-run and vehicular manslaughter. At this time, O'Sullivan said that neither drugs nor alcohol appeared to be a factor.