There are calls to re-examine the safety of electric scooters, following another death and a series of severe injuries in US cities.
Irish exchange student Mark Sands, 21, died after a collision with an Uber car in Texas, in the early hours of Friday.
A study by watchdog Consumer Reports suggested this month there had been at least 1,545 scooter-related accidents in the US since 2017.
It said cities and scooters companies needed to "improve safety".
Mr Sands had been riding a Lime scooter.
The electric-scooter-rental company said: "We were devastated to learn of this tragic death here in Austin and our thoughts are with the victim's family and friends during this extremely difficult time.
"We have been in contact with local authorities and will continue to assist however possible."
"At Lime, the safety of our riders and the community is our number one priority.
"That's why every day we're innovating on technology, infrastructure and education to set the standard for micromobility safety."
Lime told BBC News it was involved in several safety initiatives, including:
- the launch of a Lime Gen 3 with enhanced safety features, including upgraded wheels, better suspension, additional braking and improved balance
- investing more than $3m (£2.3m) in a campaign to educate riders about safety
- distributing 250,000 free helmets to riders around the world
Other riders to have died in e-scooter accidents include:
- Carlos Sanchez-Martin, 20, in Washington DC
- Jacoby Stonekin, 24, in Dallas
For its study, Consumer Reports collated information from 11 hospitals in 47 cities where scooter companies operate.
Doctors told the researchers that they had seen multiple concussions, nasal fractures and broken limbs as a result of scooter accidents.
William Wallace, a senior policy analyst at Consumer Reports, said in the write-up of the study: "Right now, a stunning number of e-scooter users are getting seriously hurt, including with head injuries
"Consumers, scooter companies, cities, helmet-makers, and safety regulators must work together now to improve the safety of these products."
A separated study published by the University of California in January found 249 patients had received treatment for scooter-related injuries between September 2017 and August 2018 in two Los Angeles accident emergency departments, including two with severe head injuries who needed to be put in intensive care units.
E-scooters have been flooding into US cities since 2017, with companies Lime, Bird and Uber all offering the vehicles, which can be hired via a smartphone app.
Bird's director of safety, Paul Steely White, said: "The number of injuries... amount to less than a fraction of 1% of the total number of e-scooter rides taken worldwide.
"Car crashes kill more than one million people each year. And for every person cars kill on impact, many more lives will be cut short due in part to their devastating impact on our climate."