The pilot’s first call was to summon any nearby tugboats.

Just half a mile from the Francis Scott Key Bridge, the Dali had lost its engine, propeller and all navigational equipment. The behemoth ship, loaded with cargo, was drifting off course with no means of steering. What the Maryland-based pilot may have instantly decided, and what experts say, is that tugboats were likely the vessel’s only chance to avoid crashing into the bridge.

But the pair of tugboats that initially guided the Dali out of the Port of Baltimore had peeled off about three miles earlier, and within minutes the powerless Dali would crash and send the 47-year-old bridge tumbling into the Patapsco River, killing six construction workers who were repairing potholes on the bridge deck.

With tugboats close by, “you have a fighting chance to change the direction of the ship,” said Henry Lipian, a forensic crash reconstructionist and retired U.S. Coast Guard lieutenant. Pushing against the ship, the tugs might have been able to guide it away from the bridge pier. “I think in this case, maybe it would have been a glancing blow or maybe they could have kept it in the channel.”

In the wake of the March 26 bridge collapse, new rules governing how long a tugboat is required stay beside a ship will likely be written, tugboat crews and maritime experts say. Tugboats are not required to guide ships through the any bridges in the Chesapeake Bay, unless the U.S Coast Guard or captain of the port orders it for individual vessels that may have mechanical issues or are navigating in poor weather conditions.

The Coast Guard and Maryland Port Administration say they don’t regulate how and when tugs accompany a vessel. The Port Administration said the pilot and the ship’s captain have the discretion to decide when tugs peel off from a vessel. Maryland’s pilots, with decades of maritime experience, board foreign container ships and guide them up and down the bay’s deep channel. The Maryland Pilots Association, which is governed by the state and deploys each pilot, declined multiple requests for comment.

In the port of Baltimore, how far tugboats accompany ships varies widely, according to a Banner analysis of ship location data from MarineTraffic.com. When leaving the port, pilots often decide to call tugs off well before passing under the Key Bridge. The Dali’s two tugs peeled off about 2.9 miles before it crashed into the Key Bridge. In the week leading up to the crash, cargo ships dismissed their tugs as far as 3.2 miles from the bridge.

On the other hand, tugs stayed with the MSC Toronto, a container ship that left from the same marine terminal as the Dali just hours before, until after it had gone under the Key Bridge and started making its way down the Patapsco River.

“Any big maritime incident like this is always followed up with big legislation,” said Dan O’Brien, who has operated a tugboat in Norfolk, Virginia, for 10 years. “The changes they make after this disaster could change how we do our jobs.”

He referred to the tragedy in 1989 when the tanker Exxon-Valdez, guided by a tired crew and one tugboat, ran aground and spilled 5.8 million gallons of oil into Alaska’s Prince William Sound. In 2014, the U.S Coast Guard issued a rule requiring at least two tugboats to escort tankers through the sound.

In Curtis Bay, 12 years before the Key Bridge collapse, a pilot traveling at 9.6 knots realized his 477-foot tanker was not turning fast enough to avoid crashing into the Curtis Bay Coal Piers. He had called off his tugboat prior, and following the impact the ship’s company was sued for $5 million for injuring a dockworker. An investigation by the Coast Guard determined that four previous ships had avoided accidents in the area by traveling at slower speeds and keeping their tugboats engaged to help with the turns.

In the Chesapeake Bay, current federal regulations require ships to have a pilot or other person with experience navigating local waters before entry. Another federal regulation requires vessels known to be “difficult to handle” to receive tug assistance, but no number of tugs is stipulated. Ships carrying dangerous cargo through the Chesapeake can be prescribed a certain number of tugs, but that decision is up to the captain of the port.

Standard practice is for the pilots to have control over when the tugs are called and how long they follow a ship, according to O’Brien. Often, at least two tugboats will greet vessels after they pass the Chesapeake Bay Bridge Tunnel. Two pilots will be are enlisted to guide the ship, one certified to navigate the harbor and another for the Chesapeake Bay, although some pilots are certified to do both. Federal regulations require a pilot familiar with local waters to be onboard.

Other codes mandated by the U.S Coast Guard include: Only one pilot is required to enter the area; unwieldy vessels are required to have tugs “sufficient enough to afford safe passage”; and ships carrying dangerous cargo through the Chesapeake Bay can be prescribed a certain number of tugs, but that decision is up to the captain of the port.

It’s like “trying to land a plane on the tarmac,” O’Brien said.

Ships are growing in size, making them less maneuverable and the work of tugboats saddling up to them as they enter speeds of up to 10 knots more perilous, especially while passing under a bridge when winds are strong. In these scenarios, a pilot’s commands are critical.

Another tugboat captain from Baltimore, who declined to reveal his name for fear of company retaliation, said he is confident the tugging industry will change after the Key Bridge collapse, most likely with tugs being required to escort massive vessels through the bridges on the bay.

Under normal circumstances, the tugs will meet incoming ships just inside the Key Bridge for docking, whereas a ship leaving the port’s Seagirt Marine Terminal would release the tugboats once it’s lined up in the Fort McHenry Channel, according to the captain, who has also worked on tugboats for 10 years.

Before the Key Bridge collapse, it was common practice for pilots to navigate ships through both the Key and Chesapeake Bay bridges on their own. Taking a tugboat down the bay adds at least four more hours to the tugboat crew’s trip — time, he said, they do not have.

The harbor is “extremely busy,” the captain said, with tugboats moving from ship to ship, making every hour spent routing a vessel outside the area difficult. “It’s all up to the pilot when to release us.”.

“We’re already shorthanded with how busy the harbor is,” he added. He said his crew has worked 100 jobs in a two-week span. “If after this we have to do escorts through the Bay Bridge — there’ll be no one at the harbor.”

Cost is another issue. Tugboat are expensive, with the shipper paying between about $3,500 and $5,000 an hour for an escort. The Baltimore Banner contacted more than 20 members of Baltimore area tugboat crews to learn more about their work and concerns following the crash. Only four responded, and they declined to speak on the record, saying that they had been told by their employers not to speak to the media.

For these tugboat crews, it’s not as simple as moving to another port to find work, the captain said. Every port has its own challenges, he added, and practices that take years to learn.

Unlike in Baltimore, the Port of New Orleans has a Vessel Traffic Service operated by the U.S Coast Guard that helps vessels navigate the busy waterways. The ship’s captain and a river pilot have complete discretion over whether to employ tugs in the case of a mechanical issue or bad weather, according to Kimberly Curth, a spokesperson for the port. Across the country at the Port of Los Angeles, all tankers and vessels other than passenger ships over 820 feet long operating in the breakwater are required to be guided by at least two tugboats, according to the port’s mariners guide.

The Coast Guard has imposed tug regulations before, but they have been largely related to safety protocols and inspections, according to experts.

An engineer who spent 22 years working at the Port of Baltimore said he watched his family’s company, Krause Marine Towing, go out of business as more tugboat regulations and new technology made keeping up with other companies impossible. As the ships grew larger and the rates for a tugboat doubled his family’s rate of about $1,500 per hour, he worried about there not being enough tugboats available and employed to keep up with the ships.

After seeing the Key Bridge fall, he has continued to worry.

“When ships had any problem we took them all the way through the Bay Bridge,” he said. At times, he said, this harbor “can feel like the Wild West.”

This story has been updated to say that river pilots in New Orleans often employ tugs in cases of bad weather.