Jasmyn Chan, who died following a hit-and-run collision in Sheffield this morning, has been described as "an active, friendly girl".
Paying tribute to the 14-year-old, Chief Inspector Stuart Walne said: "Jasmyn was an active, friendly girl who was very giving.
"This situation is even more upsetting as the driver didn't stop at the scene."
He added: "The driver may not have intended to cause this collision nor are they likely to have been aware of the extent of the injuries they caused last night.
"However I would urge them to think about the impact on Jasmyn's family, friends and community and please come forward."
He said that investigating officers are working on a number of leads and that people have been giving the police information.
A 12-year-old girl who was seriously injured during the incident is being treated in hospital.
More top news
The text-to-register service allows mobile users to add their number to the Telephone Preference Service 'do not call' database.
A consumer report found that a number of once-a-day sunscreens decreased in protection by an average of 74% after six to eight hours.
It will be mainly dry across the UK, but parts of Wales and England may experience thundery showers.